Basic boat prop knowledge

                                                       

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How does a boat propeller work?

Every prop has two numbers to describe it. The two numbers are pitch and diameter. The other part of the prop is the hub, the hub is the area where the prop shaft is attached. There are three types of basic props we use on pleasure power boats and they are aluminum, stainless steel and brass. Each of these materials has special issues that are associated with its use in prop construction. Aluminum and stainless are the standard on outboard and inboard/outboard configurations where brass is used on inboard configuration. All three of these materials can be repaired with in limits.
                                           

First we will cover Pitch 
 The first number of two marked on the prop. Pitch describes the angle of the blades. A slang term for a prop is the screw and this is for good reason, like a screw  being turned into wood each turn moves the screw a measured depth in the wood. Pitch determines the amount of forward distance the prop travels for each revolution the prop makes. Pitch is measured in inches so a 15 pitch prop moves 15 inches through the water with every complete rotation. Pitch describes two things in layman's terms, imagine the pitch number describing the ability to gain traction, the lower the number the better the take off from a stand still (hole shot) your boat will be. Pitch also could be considered like a gear arraignment the lower the number the more robust the teeth on the gear would be, in other words there is less chance of skipping teeth when you suddenly increase the rotation(speed and torque) speed.

Pitch affects the top speed the boat can produce, the fuel burn your motor uses, and the pulling or pushing power that the boat can provide when the boat is moving from a standing start (hole shot).

Speed
 This is obvious if the prop will move 15 inches with every rotation and the identical motor and boat has a 19 pitch, the 19 pitch moves 4 inches through the water further than the 15 pitch prop. However this is not an unlimited number as the motor will only provide a maximum number of revolutions of the prop, the pitch becomes limited. You could not have a 40 pitch prop as you would never grab enough water to move at all as the prop would simply act like a blender and air the water and spin with no real effect. This is called cavitation, to much cavitation simply boils the water and burns the edges of the prop. So there are a select number of pitch combinations for each motor and boat combination. The magic is to find the prop which gives you the best hole shot (standing start) and the maximum top speed based on the top rpm that it is safe to run the motor.

The next number is diameter 
This is the distance from tip to tip of the prop. The diameter is also a restricted number, as it is restricted by two other items. The diameter of the prop is restricted by the size of the prop shaft. If you try to turn a large diameter prop on a small prop shaft that prop shaft will snap. The torque that the prop places on the shaft would stress the shaft causing the shaft to twist or snap it some where close to the back of the prop. The other item that affects the size of the prop is the location of the anti cavitation plate, this is the flat plate directly above the prop on your gear case. This plate is designed to be even with the water height that is created from the bottom of the boat when you are on plane. If this plate is too high or too low you will not achieve maximum performance of the motor or the boat. This plate also stops the water from simply flying out above the prop creating the maximum forward thrust that the prop develops. You do not want to have a prop which is so close to the plate or the hull that the water cavitates because it cannot pass through the gap between the prop and the anti cavitation plate. In the case of prop being close to the hull you could if you hit something cut a gash through the hull of the boat. These are the reasons why you are generally restricted to one or possibly two diameters you can use.
                                                               

The last part of the prop we described is the hub, this is the center of the prop were the blades start and the shaft penetrates the prop. There are different types of hubs on power boats, the hub is designed and dictated by the prop shaft and or gear case. in the case of an outboard or conventional inboard /out board the hub of the prop has exhaust gases that pass through this area. This is why when the water is clear you can see a trail of bubbles leaving the center of the prop. The hub of this type of prop is the same size as the gear case with open passages through the hub. There are two styles of these props, the break away hub and the fixed hub. You will only be able to determine the type you have by removing the prop off the shaft. When you remove the prop on the inside of the hub you may find a hard plastic block with a hole and splines for the shaft to pass through it. this block is designed to break away if you impact the prop to reduce the prop damage and the possibility of damaging the gears inside the gear case. The fixed hub does not have this plastic block and therefore if you impact the prop you will surely damage or break off the blades and possibly damage the gear case. A racing gear case on an outboard or inboard /outboard has a solid hub similar to an inboard configuration as there is no exhaust port requirement..

Prop materials
are aluminum, stainless steel and brass. On an inboard or inboard outboard configuration the props are made out of aluminum or stainless steel, why is this? The aluminum prop is a soft material which will easily change shape or break away under impact, this is critical to protect the inner workings of the gear case. The disadvantage to an aluminum prop is that the blades flex under load so the pitch is not a constant as you power up or are pushing the boat through heavy sea conditions. The pitch on an aluminum prop will change over time they are not reliable to always remain the same as they were made, affecting performance and fuel burn. Stainless is the next material, it is stronger and rigid so this material gives you reliable pitch through its life and while you power up. The blades do not move around. This great for performance however if you impact the prop you can damage the gear case workings. The stainless prop is more durable and less apt to be as immediately affected by corrosion. The last material is brass which is what the inboard configuration has, brass is less flexible than aluminum and not as durable as stainless. The perfect material for props that you cannot see. If you impact the blades they will flex and break away to help protect the rest of the running gear. One of the disadvantages to brass that the pitch can change with high hours of use, so it is a maintenance item to have your props tuned on a regular schedule. Doing this will keep the performance you should expect and the fuel burn correct. A prop tune is not expensive and will pay you back in fuel burn.
                                                         

Props come in several ways, there are the number of blades, the style of these blades, and the direction of rotation. There are also right hand and left hand rotation. On small outboard motors you will have two blades on more power full outboards and inboard/out boards you will see three and four blade props, the same as inboard configurations.You also see dual prop configurations on more current boats. The amount of blades can assist in achieving the best performance for a hull design, and weight. A four bladed prop can be more efficient in providing pull out of the hole and something called transom lift providing quicker hull planing capabilities. When we talk about left and right hand props this is the direction of the rotation of the drive shafts. When you have a twin configuration you are looking for the starboard drive or shaft to be turning right hand and the port providing you with left hand rotation there is a reason for this set up. In a single motor single prop the boat has a natural tendency to pull to the right going forward and to the left in reverse, by having a counter or left hand rotation on the left side it counters this natural reaction. Which creates a more manageable boat to operate. Twin with right and left hand rotation also provides transom lift, because the props turn in against each other there is a channel of water which is pushed straight down lifting the hull out of the water. This is taken advantage of the most with performance boats where the distance between the props is very small. If you have a twin that has two right hand drives there is a high chance that the drive on the left has been changed, the boat will never perform to it maximum at all. All left hand props are marked with an L, right hand props are not marked.
                                             

Choosing a Prop for your boat requires some calculations which Mercury or Volvo can provide you with based on your specific configuration. If you still feel that you can get a little more out of a prop then a prop repair person can put an extra half pitch in the prop, and yes this does work, you can get a real gain in a half pitch custom set up. Knowing if you have the right prop is an entirely separate topic to cover. When you read the numbers on your prop a 17x19 is a 17 pitch 19 inch diameter, a 17x19L is a 17 pitch 19 inch diameter left hand or counter rotation prop. These numbers are either on the side of the hub or on the end of the hub. If you are not sure a prop repair person can tell you what you have.

There is a mass amount of science to prop construction, materials, and selections. This article was simply to cover basic information, to create a basic understanding. A duo prop drive has one prop turning right and one turning left, so a single duo prop will not have the natural pull to the left or right. Duo prop provides a more stabile steering and control platform. IPS and the new forward drive are all duo prop configurations. If you need more information on props Mercury is running information this year on this topic.

Ask BNM about our new 2015 Services

To guarantee access to all of  Boat Nut Magazine articles, pictures and featured services visit the official Boat Nut Magazine ©™ website. Be sure to reply to the Boat Nut Association registration on our site for the latest Boat Nut weekly and monthly news letters and opportunities.

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Copyright 2015 © Boat Nut Media, Toronto, Ontario. All rights reserved. No part of this information/publications may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, magnetic, or other record, without prior agreement and written permission of the publisher, Boat Nuts Media ©™ No liability is assumed with respect to the information provided.

Telemarinetech part 2 BNTN Program

                                                         

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Telemarinetech the best tool you will have as a boater, we field all questions you may have!

Please Email boatnutmedia@gmail.com to receive more information and an application

You can read over the information and look at the application before you commit to the program, There is no limit to the amount of times you use the service. Any question any time BNTN is the perfect addition to your boat ownership plan. Boat Nut Media guarantees your satisfaction or you will get a full refund. The specialists that will help you are hand selected marine technicians who can explain your answers in an easy to understand language.

You now have an expert available to you 7 days a week, Our specialists believe that any question is a good question we want you to be informed about your boat, because when a problem comes up you are usually on your own. It is rare that you have a problem with an expert on board with you. The idea for this program stems from the days when I was in the boat service business, My clients were able to call me anytime, my phone used to ring over 21 times before noon almost every day from boaters who had questions ranging from mechanical failures to what size anchor do I need. With break down questions we could get the boat running 99 percent of the time over the phone and save the boating day or trip! Telemarinetech is not trying to take the place of your marine mechanic ,we are designed to be a support program for you.

This program is ideal for  New Boaters who are just starting to boat, Boaters who cruise distances, and Experienced Boaters who just need to make inquires to verify that what they are dealing with is accurate. We can take the time with you that a service technician cannot always give you

Telemarinetech/ BNTN details at boatnutmedia@gmail.com
on our blog, and on twitter @BoatNutMedia

To guarantee access to all of  Boat Nut Magazine articles, pictures and featured services visit the official Boat Nut Magazine ©™ website. Be sure to reply to the Boat Nut Association registration on our site for the latest Boat Nut weekly and monthly news letters and opportunities.

http://boatnutmagazine.com/

Copyright 2015 © Boat Nut Media, Toronto, Ontario. All rights reserved. No part of this information/publications may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, magnetic, or other record, without prior agreement and written permission of the publisher, Boat Nuts Media ©™ No liability is assumed with respect to the information provided.

TeleMarineTech

 

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Your TeleMarineTech Appointment



Contact:
BoatNutMedia@gmail.com

 

Overview of a Marine TeleMarineTech appointment
. . . just like a regular Marine Technician service inquiry appointment

You have got to the boat on Sunday and it won't start, you are on the lake and have an alarm going off, you have a service question or need advice about the boat, your boat has broken down and you want to verify the information a service provider has given you, is the estimate for repair accurate, you are looking at buying another boat? You will meet using Boat Nut Telemarinetech Network, BNTN uses video conferencing to connect you so that you will not have to worry about were you will receive non bias assistance. This will reduce the time, cost and stress associated with a sorting out a service issue and boat ownership.

What is a TeleMarineTech visit?

Telemarinetech uses video cameras, and Skype/Zoom services to connect you to marine specialists who are not located near you, reducing the need to locate and wait for a service appointment and receive assistance the assistance you urgently need. You will be able to see, hear and talk to a certified technician or other marine repair professional. (not all marine trades are recognized with certifications, "specialist")

How does a Telemarinetech service visit work? 

A telemarinetech appointment is just like a regular service appointment; only the specialist you will be seeing and speaking with is on your monitor.

Before you call, the specialist will require the hull ID number and the Serial numbers for your motors, drives, relevant information about your boat to support your telemarinetech visit. However you may be asked to provide assistance with tests for results. The video conference connection is made with the specialist at a different location and the visit begins.

The marine specialist may request your assistance or assistance with your camera to provide video, to complete the examination. The specialist on the monitor can hear an alarm, see broken parts and use your assistance to diagnose service questions the same as if he/ she were standing on the boat with you.

Is there a cost for a telemarinetech appointment? 

NO, You will not be billed for this service, if you are a registered Boat Nut. It is covered under the Boat Nut Membership Benefit Program "I AM A BOAT NUT".

Is Telemarinetech private?

Just like a regular service appointment, your Telemarinetech visit will be private and confidential. It can only be seen and heard by the specialist involved.

Where can I get more information about Boat Nut Media?

If you have any questions, please speak to a  boat  nut representative at 1-416-418-7433. You can also visit Boat Nut Media at www.boatnutmedia.blogspot.ca or Email BoatNutMedia@gmail.com.

As a non bias power boat information and education provider in Canada, we feel by creating Telemarinetech service we are helping boaters get more out of their boat ownership experience. Providing more boaters with the care they need, were and when they need it. Our innovative use of todays and tomorrow's technology streamlines the service process, eliminating unnecessary wait times, assisting in an emergency and giving all boaters the same access to marine technicians and other marine professionals (specialist). Through our experience and insight, we have expanded the way knowledge is shared and how the marine community interacts. The information gained enables boat ownership budgets to go farther. For more information go to www.boatnutmedia.blogspot.ca

 

BNTN  BOAT NUT TELEMARINETECH NETWORK  2015

How to be a Boat Nut?

Telemarinetech Service are available for Boat Nut Members; 7 days a week 7 AM to 9PM Central Time in Canada. You will be assigned a professional to assist you with your service question(s). 2015 Membership Fee are as follows: The same price as a screw driver set at Canadian Tire, BNTN Service is the most valuable tool you will have on your boat!

One year Membership Fee $25.00 Canadian for the first 200 Members to sign up.

After the first 200 members the full fee rate will apply $55.00 "I am a Boat Nut"

Telemarinetech Services will be available starting April 7 2015, Services are only available in English.

You will receive a BNTN Membership Card and access phone number (App is being developed will be available when complete)

You will have to complete the application which will ask you basic questions Name, Address, Email, Boat ID number, Motor and Drive, and systems. We do this so we can develop base line information on your boat to make answering your questions quicker and more accurate.

To guarantee access to all of  Boat Nut Magazine articles, pictures and featured services visit the official Boat Nut Magazine ©™ website. Be sure to reply to the Boat Nut Association registration on our site for the latest Boat Nut weekly and monthly news letters and opportunities.

http://boatnutmagazine.com/

Copyright 2015 © Boat Nut Media, Toronto, Ontario. All rights reserved. No part of this information/publications may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, magnetic, or other record, without prior agreement and written permission of the publisher, Boat Nuts Media ©™ No liability is assumed with respect to the information provided.

Spring start up / Boat Restoration 1998 280 Bayliner

                                         

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BOAT RESTORATION  Project #1 1998 BAYLINER 280

Boat Nut Media thought it would interesting to follow several spring start up boats this year, we have tried to select a cross section of different boats and budgets. Saving the dream! Boat Nut Media has selected a 2001- 410 Silverton Yacht (Sport Bridge),1998-280 Bayliner (Cruiser), 2001- 260 Sea Ray (Small Cruiser) and a 2010- Center Console fishing boat (Fully Rigged with Kicker, Radar, Down Riggers, all the toys)

2015 Spring Project Boat  1998 Bayliner 28 Cierra

List of spring work to be completed: 

1- Restore the exterior of the alpha drive

2- Replace the universal joints

3- Alpha Drive spring service - Gear Oil, Water Pump, Prop Repair, etc.

4- Gel coat repairs to hull on Port and Starboard sides and the back edge of swim platform

5- Replace hull graphics

6- Polish and wax the whole boat

7- Repaint the wiper arm components

8- Replace the haws pipe at anchor locker

9- Replace the horn

10- Replace the VHF radio

11- Repair the wood grain dash all the printing is gone

12- Replace the fridge

13- Clean up the interior like new (remove mildew stains)

14- Clean up and restore exterior upholstery

15- Spring start up on 5.7 liter motor. Fluids, paint the works.

16- Replace the dockside water fitting

17- Replace the Bimini and install tonneau cover

18- Full systems check and repair any failures 

19- New bottom paint
20- New prop

After all work is completed there will be a sea trial and delivery to a new marina. The reason for all this work is the boat has only had 1 hour of operation time in the last 3 years. Boat Nut Media will video the boat at the start of the project, and take you through the project to completion. Work will begin late this week, we will upload videos every two days. If you have a similar projects on your boat you will see the products and procedures that are used to make this boat look like new again.

Bringing this boat back to its former pride and glory will be a lot of work. This is one of those boats that begs the question, what do you do and were do I start? Do you let it go cheap or spend the time and money and bring the boat back to a clean reliable boat. There are a lot of these types of project boats out there and not all of them are worth repairing. Why do boats end up in this condition? Well for whatever reason the owner has not had time, has lost interest in the boat, or cannot afford the boat. How do you determine which boats to save? Boats like this one reach a tipping point, and this one is right on the cusp. Another year of no use and no interest would have pushed it over the edge. This is when the cost to repair starts to exceed the value.

Here is an example of a 2010 Bayliner 260 after one season abandoned at the dock

This boat was chained to the dock with a smashed out port cabin side window all of last summer. The boat literally was frozen when Boat Nut was asked to get it to the ramp! This boat will be for sale this year would you want to be the next owner? There are always tell tail signs of a boat that was abandon or let go. For information on how to detect this type of boat check out Telemarinetech Services from Boat Nut Media.

 If you get to this point you should have sold the boat the first year that you were not using it. If you do not have the budget, the time or the want to repair your boat sell it ASAP take the loss and walk away. Even one year of no use or hours really hurts a boat. This 28 Bayliner will take weeks of time and a large budget to bring it back to where it should be, the fortunate part about this story is the boat has been put away every year correctly. Boats that have been left by owners who have lost all interest rarely seek the correct seasonal services. So luckily in this case the important parts of this boat are still in good shape, the motor, the structure etc. So with the right planning this boat will be one to be proud of again. This boat is going to receive this work not for a profit but for the love of the boat.

Fixing and flipping can be a risky proposition and you can be with the boat for some time. There is no sure thing. I have seen sure fire flip boats be for sale for three years you must be prepared for this or cut your losses.

At the end the boat will either be loved again or it will be sold. No matter what the out come this boat is going to enter the second stage of its life.

 If you are a do it yourself boater this 28 Bayliner would have been a great candidate for a fixer upper, and that cannot be said for too many loss of interest boats out there. Do not be fooled by the story, the boat has had no use in the last couple of years so this boat will be in better shape than a boat that has been used regularly. That is bull, the boat that has been used and maintained will ninety percent of the time the better boat. If you are considering buying a fixer upper this project will be one to follow. You will certainly get a feel for what it takes to restore a mid size cruise.

Boat Nut Media will include the costs of labor and parts for each step, giving you an idea of how much of a budget is necessary, and how to manage this type of project.

Telemarinetech information is available on our next blog and at boatnutmedia@gmail.com

To guarantee access to all of  Boat Nut Magazine articles, pictures and featured services visit the official Boat Nut Magazine ©™ website. Be sure to reply to the Boat Nut Association registration on our site for the latest Boat Nut weekly and monthly news letters and opportunities.

http://boatnutmagazine.com/

Copyright 2015 © Boat Nut Media, Toronto, Ontario. All rights reserved. No part of this information/publications may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, magnetic, or other record, without prior agreement and written permission of the publisher, Boat Nuts Media ©™ No liability is assumed with respect to the information provided.

Basic Bravo Three and Volvo Duo Prop Service

                                                           

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Basic Bravo Drive Service / Volvo Duo Prop Service

                             

Be sure to also read the Alpha Basic service blog as there are details that will cross over and apply.
Bravo  drives are easily identified  by their size, Bravo drives are much larger in size and are most identified with duo prop configuration. There are three common generations of Bravo drives. The first is the single prop bravo drive most common on boats from the 1980's, single prop drives are similar in service to the alpha drive only larger in size. It is the two Duo prop generations that we want to focus on in this service information. The reason why I have included the Volvo Duo Prop drive with the Bravo Three duo Prop are they are very similar to complete a basic service on.

There are some specialty tools you will need to purchase from your mercury or Volvo dealer to complete service. this is because the gear oil drain is located behind the props.

1-  Prop Nut socket kit from Mercury Marine (Mercury will not fit Volvo)
2-  Prop Nut Socket kit from Volvo Marine (Volvo will not fit Mercury)
3-  Large straight screw driver for vent screw (Mercury)
4-  Large set of metric Alan wrench's for drain screw (Volvo Marine)
5-  5 one liter bottles of High Performance gear lube (Mercury Marine)
6-  Volvo synthetic Gear lube from Volvo, you must use the synthetic gear lube in your Volvo drive        do not use Mercury High Performance
7- Mercury Zinc Chromate primer (Mercury Marine)
8- Mercury Phantom Black Spray paint (Mercury Marine)
9- Volvo zinc Chromate primer (Volvo Marine)
10- Volvo silver color match drive paint( Volvo Marine)
11- Anode replacement kit for either Mercury Bravo Three Drive or Volvo Duo prop drive( you may require the drive serial number to be sure you get the correct parts. For Bravo Three you will locate the drive serial number on the top motor cover. On a Volvo you will locate the serial number for the drive on the motor cover.
12- Mercury 2-4-c grease this can be used on either drive.
13- Grease gun with underwater grease by either Mercury or Volvo.

In either drive service case you will need a oil recovery container (oil drain pan). You will also need a one foot cut length of 2x4 to use as a prop wedge. The first step is to remove the props. Trim the drive down to a comfortable position to access the prop nuts and remove the props. Place the 2x4 wedge in between the edge of the large prop and the anti cavitation plate above the prop so the props cannot turn when you apply pressure with the correct prop nut socket on the small prop. These nuts may be very, very tight, they loosen by turning to the left. Once the small nut is removed you may find the prop tight to pull off, place a wooden block against the back of the prop on of the back of the blades and give the block a hit with a mallet, do not smash the block simply work your way around the blades until the prop pops off. Do not let the prop fall on the ground they are finally tuned stainless and can be bent with a fall onto concrete or hard surface. This will expose nut number two the large prop nut . Place the 2x4 in the same location between the end of the blade and the anti cavitation plate and loosen the same way. Once nut is removed take off the prop.

You will now be able to see the drain screw in the very bottom of the bullet or gear case facing you. You will now need to trim the drive all the way down with the oil change tray under the drive, with the skeg set over the middle of the pan. You will then remove the drain screw which will have a small ring gasket on it. Then you will remove the vent screw which will be on the side of the gear case up high on the right hand side of the case. If you have a Volvo Duo Prop drive you can also remove the dip stick which is in the top middle of the gear case it looks like a large bolt with a slot for a screw drive in it. Now you will need to leave the drive for a couple of hours to completely drain down, this will also drain the reservoir bottle on the engine at the same time. Do not rush this.

While this is going on its time to inspect the condition of the drive and the anodes. If the anodes show any bad break down or are missing install new ones, the kit will provide you with details of were to look for all the anodes that can be serviced. If you have areas were the paint is damaged then you will need to re spray and paint in these areas . Do not unless absolutely necessary sand and paint the whole drive. If you do this you are starting a process that will never end you will be painting the drive every year., the products that the drive was coated with from the factory are the best and are almost impossible to reproduce. Once you sand the drive you are immediately promoting corrosion. Do not paint any anodes they will not work if they are coated with paint. If you paint the anodes the props will become your anodes!

When you are sure that all the gear lube is drained it is time to refill. Hook the gear oil pump up to the drain screw hole and begin to slowly pump gear oil into the drive with the large duo prop drives stop every five minutes and let the air get on top of the lube, a two min break is good enough and then continue to pump slowly until the gear lube is showing at the vent. Now leave every thing hooked up and take a ten minute break, come back and pump a little more until the slow flow out of the vent screw hole is steady with no air sputtering. Now you are full. Grab the drain screw and install a new seal ring and do the same to the vent screw. Install the vent screw (and in the case of a Volvo put the dip sick back in finger tight). Now remove the gear lube pump and replace the drain screw.
and the vent screw. In the case of the Volvo Duo Prop you can confirm the gear oil level with the dip sick and then replace and tighten the dip stick.

With the drive full of gear oil you must now go into the boat and fill up the reservoir on the engine . On the first trip you must recheck the level in this reservoir and if it drops some top it up. This is important and like the alpha reservoir there is a sensor and alarm on this bottle, if the gear oil level goes down to a low level it will send you a signal by providing a constant beeping at the dash when the ignition is on. I noted in the alpha service blog that the reservoir must be connected through the wire harness, if the sensor is not plugged in or the wires are modified get them fixed. Without this warning you will not know that the drive is consuming gear oil and the worst case the drive will blow up. If through the year you need to keep filling the reservoir then contact your authorized service provider and have them do a pressure test on the drive, and have the drive fixed if gear oil can escape then water can get in. This is a recipe for disaster.

                                                   

On a Bravo Three Drive or the Volvo Duo Prop it is important that the trim up and down is smooth and even , If the drive trim is slow to react or the drive jolts on the way up or down you will need to grease the trim ram pins there are two one at thee front of the rams and one at the back, the way to do this is to remove the plastic end fitting on the ram pin, under this you will find either a nut or a clip remove one side and slide the pin out of one ram side only place some grease in the hole and slide the ram back in and reverse the procedure for the other side. try to do one side at a time if you remove the whole pin then you need to man handle the drive back into place to slide the pin through all the holes. In the case of a Mercury Bravo Three there is a yellow plastic spacer in the drive itself that must be re installed the correct way or your drive will not trim all the way down. In most cases this job can be a little intimidating and you may want to let your service provider handle this.

There is no sea water pump in a Bravo Three or Volvo duo prop. So gear oil change, placing some grease on the prop shafts, a little paint, anodes and your basic service is done. If you see any zirk fittings for a grease gun to hook on give them a couple of pumps of grease and away you go.

Things you must be aware of with Bravo Drives:

1- Do not operate the shift unless the motor is running, all you are doing is stretching the shift cable
    this will cause shift problems.
2- If you have Bravo Three drives and are a fishing nut then you are likely stressing the universal           joints and should have the drive pulled every year to keep an eye on the universal joints.
3- Gear oil changes are key to the drives ability to sift because of the cone clutch.
4- If you run fast a lot with the Bravo Drive the bearing at the very top of the drive gets hot and will       burn up, there is a kit you can buy that pick up water and dumps it on the top of the drive to cool         the housing and bearing, if you are running long distance it is a good idea to slow down and let the     top of the case wet down and cool occasionally.

                                                   

Example of a Bravo Shower

5- Keep your props in good shape if you run with banged up props it is hard on the prop seals.
6- Set out a service schedule were you have the drive pulled at regular hourly operation times or             annually for drive shaft, bearing and bellows inspection and service.
7- If you have damage to the skeg or cavitation plate get this fixed, the aerate water around the props       will be disturbed and you will loose performance (this is true for any drive)
8- If when you drain the gear lube the gear lube looks like a milk shake or has any water in it call            your service provider and have them pressure check the drive.
9- Always replace the ring seals at the drain and vent screws after any service.

                                         

Mercury Duo Prop Tool

Things to be aware of with Volvo Duo Props:

1- You actually loose less horse power through a Volvo drive.
2- You have a dip stick in the top of the drive to check fluid level after you change the gear oil.
3- Under the front cap of the drive There is the shift shaft this are should be lubed up to prevent corrosion, as there is a seal here that can allow water into the drive and if it is not lubed can create stiff shifts.
4- You must use Volvo synthetic fluids appropriate for your application.
5- If you are buying parts for your Volvo Duo Prop be sure of the serial number, and only by genuine    Volvo parts as after market parts quite often will fit but are not exactly right and you will be                 repairing again in a season,
6- Do not try to remove the props without the right tool if you knock off any of the raised bumps on       the nut you will end up having to cut the nut off.
7- Arrange with your service provider regular dive pull service to inspect the drive shaft, bearing and     the bellows this should be based on hours of operation or annually.

                                       

Volvo Duo Prop Tool

When we discuss service based on hours the standard is usually every 100 hours of operation or every year. A key fact is that most Inboard /Outboard boats that sink ,the cause is the bellows. The bellows are the rubber boots which surround the drive shaft and the shift shaft, some drives have exhaust bellows also. With age these bellows begin to crack and water starts to trickle in, a dead give away for bellows that are going bad is when the drive is pulled and there is water in the bellows and or the drive shaft is all rusty. Because of the proximity of the bellows to the water (under water) this is a repair you should have an insured and certified service provider complete the installation can be tricky and requires experience . Done wrong and your boat is on the bottom. This is why it is recommended not to store the boat with the drive trimmed up for long periods of time, if you have muskrats in your area they love to chew on the exposed bellows. So keep your drive in the all the way down position as much as you can.

                                           

Example of Bellows Kit

Never attempt a repair that you feel is over your head if you require detailed service information Email: boatnutmedia@gmail.com  and we will help you with any questions you may have.

To guarantee access to all of  Boat Nut Magazine articles, pictures and featured services visit the official Boat Nut Magazine ©™ website. Be sure to reply to the Boat Nut Association registration on our site for the latest Boat Nut weekly and monthly news letters and opportunities.

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Copyright 2015 © Boat Nut Media, Toronto, Ontario. All rights reserved. No part of this information/publications may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, magnetic, or other record, without prior agreement and written permission of the publisher, Boat Nuts Media ©™ No liability is assumed with respect to the information provided.

Spring Boating : How to know if the boat is running the way it should

                                                           

 

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How do you know if your boat is operating right?

There are a set of simple test tricks to know if your boat is performing the way it is expected to.
Your boat has a basic set of parameters dictating performance expectations that the builder released when the boat was originally sold new, these numbers are an idea in most cases. These parameters would have or could have included information such as top speed, RPM at full throttle, weight of the vessel with full fuel and water, fuel burn expectations, etc. However after some engine operation hours your horsepower numbers will begin to drop off, the weight numbers will vary from boat to boat simply because some boaters will keep a lot of gear and items on their boat , other owners will have next to nothing. If you start to add accessories like a tender, radar arch, swim platform extension, a replacement swim platform or adding a big generator. Then you have definitely changed the weight of the vessel and could possibly have changed the center of gravity and created a load shift backward/forward or side to side of the vessels center line.

Changing the load from the center line or changing the center of gravity will totally change the expected performance of the hull and the way the boat rides on the water. Large loads can create changes that the hull cannot recover from, an example of this is when the load shift from center line will no longer allow the hull to get on a natural plain position. The bow will simply not drop. The only way to fix this type of problem is to start changing props, modifying or installing a hook in the hull, this is a type of permanent trim tab. You can also add more weight to the fore ward hull. All of these modifications can bring the bow down, however all these modifications will mean that your fuel bill will climb substantially. A really good accessory designer will keep this information in mind and recommend installation location instructions specific to your make and model of boat. Adding accessories like extended swim platforms can really affect the performance of the hull when backing up or travelling in following sea conditions.

This means that the new swim platform can act like a trim tab and keep the hull from rolling from bow to stern. This can create lift at the transom and make the boat very "transom loose". Which creates a situation were you loose the ability to steer the boat. In the worst case of operation in a following sea the back of the boat can be lifted up and come around to try and pass you. This is when the weight of the boat is being placed on the mounting point of your new swim platform and the water can rip it off.

Other situation that can be created is a "list" when the load weight is not even from side to side, this situation is enhanced at high speed. The boat starts to lean over and becomes unstable. You can try to correct this with trim tabs but if this is a must all the time you must address the list. If you continue to run a boat with a list you will eventually stress the trim tab and the trim tab ram or trim tab will eventually give up. Balance from side to side is far more easily addressed than any other balance problems . The load on the boat can be moved around, the best place to start is with the batteries etc. If you find the boat is listing and slowly getting worse you may have a leak, and a floatation locker maybe slowly filling up. This type of leak can go on for a long time and never show any water in the bilge. To figure this problem out you will probably need to bring in a surveyor to tell you were this maybe taking place.

When it comes to the engine there are some simple tell tail signs that you need to have some mechanical work done. What you need to do is start by reading the water, this means on a nice calm morning start the motor or motor(s) one at a time. Immediately go to the back of the boat and look at the exhaust water and the water around the back of the boat. If you see a slick of gas on the water then the motor is not cleanly burning all the gas it is consuming. This is the sign of requiring at least a tune up. If you have twins with thru hull exhaust check the water flow against each other, if one motor flows more than the other then you probably need to change a sea water pump impeller in the motor with less flow. This same trick can be used for inboard out board units. With the engines off trim the drives up and down and look for any oil slicks if there is a leak in a seal the small leak will create a slick on the surface of the water. For trim tabs use the same test. Any kind of slick is a sign that something is wrong! The water around the back of a boat that is running right will be clean.

The exhaust smoke color can also tell you a lot about what is going on with the motors. White smoke is usually just steam. A little bit of white smoke is not a horrible thing on start up or after a long run coming off plain but it should clear up quickly. However white smoke that has a sweet smell means that you are burning antifreeze from your closed cooling system. Black smoke is carbon, which may just mean the boat needs a good high rpm run to clean up and heat up the motor, or it could be a sign of bad spark plugs. Blue smoke is oil, this is a sign that you have a motor that is getting tired, if it is just blue at the start then you have a valve train or ring problem and again will need to get this fixed. This means some type of engine tear down. Any off the above problems will affect the performance of the motor(s) and this will affect the boats performance.

Take the boat for a ride and bring another driver with you. This is so you can read the water again. The information you can get from this is interesting. Look out the back off the boat while you power up through the rpm range, watch the wash coming off the back of the boat it should be even on both sides, when you do this "do not" use the trim tabs at all. Look at the prop wash and you should see a nice even flow of water, if you have twins the wash should be the same on both sides. When you get to 2500 plus rpm with twins if you match the rpm's on port and starboard motors the boat should start to sing. The sound will be even and matching (the sound should be like one motor). When this happens, run the boat like this for 15 min or so the sound should remain even and solid you will hear it if a motor starts to lag or miss immediately. With some experience doing this you will easily be able to pick out the motor that is acting up. Now take a peak up the sides of the hull and see were the water is breaking out from under the hull and how far the spray travels this will let you know if you are running with any list on plain.

When you are out for your ride you can test the rpm ranges of your motor(s), you should have push all the way from idle speed right through the range. Check the following. When you push the throttle and the rpm increases quickly but the boat is slow to react or it sounds like the motor is not loading up (Slipping), or at the top end of the rpm range the maximum speed of the boat is obtained way before full throttle is obtained, and the last of the throttle range just increases the rpm only, These are signs that you have to re prop. The best way to do this is to call the engine manufacturers and they will ask you a series of questions to determine the best prop for the performance you are trying to achieve, improving the prop can make a huge difference in performance and fuel burn.

These are simple tips but they really do work try them out on your boat or your friends boat. Reading this is may explain why quite often a mechanic will start the boat and step off the back and stare at the water he/she is reading the signs the boat are giving. A lot of times problems will show up here first before a break down. A boat is much like a car, it will tell you what is wrong, most cases long before a larger problem arises, the trick is to know what your boat is telling you.

To guarantee access to all of  Boat Nut Magazine articles, pictures and featured services visit the official Boat Nut Magazine ©™ website. Be sure to reply to the Boat Nut Association registration on our site for the latest Boat Nut weekly and monthly news letters and opportunities.

http://boatnutmagazine.com/

Copyright 2015 © Boat Nut Media, Toronto, Ontario. All rights reserved. No part of this information/publications may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, magnetic, or other record, without prior agreement and written permission of the publisher, Boat Nuts Media ©™ No liability is assumed with respect to the information provided.