If you are upgrading from a three blade to a four blade propeller, remember that a four blade propeller generally uses up to 50 to 100 rpm more than a three blade prop with the same pitch.

Four blade propellers…

Images and some verbiage were courtesy of Brett at BBlades Professional Propellers.  He's been a great resource and I encourage you to contact him as follows:

  Email him HERE

Back to top

Temperature Problems

WARNING:  IF A TEMPERATURE PROBLEM IS SUSPECTED, BE CAREFUL.  THE COOLING SYSTEM CONTAINS HOT LIQUID UNDER PRESSURE AND A CARELESS OR THOUGHTLESS ACTION COULD RESULT IN SEVERE INJURY.

TEMPERATURE GAUGE PROBLEMS

Before spending any time trying to diagnose a temperature problem, make sure that you really have a problem.  Temperature gauges, especially the electric type, which are the most common in boats, are often very inaccurate and have temperature scales that are difficult to interpret.  Therefore, before worrying about a suspected temperature problem, check your temperature gauge against a thermometer of known accuracy.

NORMAL TEMPERATURES

Most marine FWC thermostats open at 160 degrees F and will be fully open at approximately 180 degrees F. A new clean system under moderate load should operate at the lower end of this range and a dirty system under full load might operate in the upper range.  Anything outside of this is abnormal and should be investigated.

OVERCOOLING

The most common problem is a temperature above the thermostat range--overheating.  The opposite may also happen and will create long term problems.  Any good FWC system should have excess cooling capacity.  This compensates for the inevitable decrease in cooling capacity that results from the normal gradual buildup of dirt on the heat transfer surfaces.  In order to make sure that such a system, when new and clean, does not overcool, a thermostat is used to control the flow of coolant to the heat exchanger.  An overcooling problem therefore, has a single simple explanation.  The thermostat is not functioning properly.  Check to make sure that it is of the right type and properly installed.  Do not assume that just because it fits it will function right.  There is a lot more to thermostat design than most people realize.  Do not experiment with unapproved thermostats.  If the right type and correctly installed make sure thermostat functions properly by immersing it in hot water of known temperature.  Easiest way is to use a pot of water on a stove with an accurate thermometer.  Hold thermostat by the flange with a pair of pliers.  Do not let either thermostat or thermometer rest against bottom of pan.

Thermostat should open at temperature marked on it and be fully open approximately 20 degrees F higher.  It should close again when immersed in colder water.  Malfunctioning thermostats cannot be repaired, they must be replaced: Make sure you get the right type.

OVERHEATING

Overheating problems can be categorized into three basic problems that either alone or in combination with one another, will create overheating. They are: lack of raw water flow, lack of fresh water flow, and heat exchanger defects.

LACK OF RAW WATER FLOW

Lack of raw water flow will show up as an excessive increase of the raw water temperature as the raw water passes through the cooling system.  Normal temp increase varies between different engine models but is usually in the range of 40 - 60 degrees F. In other words, if incoming raw water temperature is 70 degrees F, the outgoing water passing through the exhaust elbows will be in the range of 110 - 130 degrees F. This will create surface temperatures on the elbow that will be warm but not excessively hot.  So the easiest way to identify a raw water problem is to check whether or not the engine overheating is combined with excessive temperatures on the outlet side of the raw water system.

If the raw water side is to blame there could be three basic reasons.

Over a few years, a problem with rust buildup in the exhaust elbows may develop.  Many exhaust elbows have several small holes in the area where the raw water enters the exhaust pipe.  These orifices are designed to ensure proper water distribution at this point.  Unfortunately, because of their small diameter they tend to get clogged with the rust particles that a raw water-cooled elbow gives off.  Eventually, an exhaust elbow may get completely plugged up preventing raw water from entering the exhaust pipe and thereby creating a fire hazard.  In an in line engine with a single exhaust elbow, this complete blockage will automatically cause engine overheating before the exhaust overheats.  This will signal a problem before a fire hazard develops.  In a V-type engine however, the situation is more dangerous since one elbow could become plugged and the other one not.  In this case, sufficient raw water may be able to exit through the open elbow to keep enough raw water flowing through the engine heat exchanger.  The engine may not overheat but the plugged elbow and matching exhaust manifold and exhaust pipe could burn and be destroyed.  We recommend that you periodically during the season feel the exhaust elbows to make sure that they stay at a normal and even temperature.  Clean or replace these elbows before they cause further damage.  Periodic flushing of the engine with fresh water will help minimize these problems.

Back to top

Outdrive Temperatures

If there is a continuous need to remove a white chalky deposit from the top half of your drive, it's probably running TOO HOT!!!

     The white chalky deposits means that the casing of the drive is hot enough to boil off the water that is splashed onto it.   This boiling process turns the water into steam and leaves  the mineral deposits behind to bake onto the drive.  The hotter the drive,  the more deposits that are collected and the harder they are to remove.   Other signs that your drive may be running too hot is paint discoloration, or  a cloud of steam that appears every time your boat comes off plane.  Unless you have opened through hull exhaust, what you are seeing is not exhaust, it's steam that is generated when a hot drive is plunged into cool water.  This process of heating and rapid cooling is known as thermal shock and can be detrimental  to metal components, especially aluminum, if the range is extreme enough.

     Keep in mind that however hot the casing is, the components inside are running much hotter.  Published  test results show that some stern drives components operate in excess of 350 degrees  F.  If you are experiencing any or all of the above conditions, your drive is probably operating over 250 degrees.  For the same reasons that automotive engineers established approximately 200 degrees as an optimum operating temperature  for their engines, most marine experts agree that this also holds true for stern drives.

     Q: What is the maximum temperature that a drive can operate at before it completely fails.
     A: Even MerCruiser will admit that 300 degrees is flirting with disaster. That's the temperature at which the oil begins to foam and break down.

     Q:  Why doesn't  the manufacturer offer a cooling system?
     A: They sell parts and oil instead. In the article "Drive Showers Useful On High-Performance Boats" in the November issue of Powerboat Reports, Editor Christopher Landry asked Pete Coen from Mercury Marine about drive showers. His response was "Those without drive showers simply must have their drive oil changed more frequently."

     Q: Do I need one on a pleasure boat or are they just for performance  boats?
     A: The type of boat and/or horsepower rating is not what causes overheated drives. 
In the article "Way to cool" that  appeared in Poker Runs of America Magazine, Editor Peter Tasler asked Mercury Racing why they didn't install drive showers as OEM equipment? Their response was, "Mercury Racing designs its drives to handle a certain horsepower range and the temperatures associated within that range, in typical boating environments."

Back to top

Restoring the Shine to Fiberglass

The outer surface of a fiberglass boat is normally a special resin called gelcoat. Gelcoat has little structural value-the underlying laminates of resin-saturated glass fabric provide that-but gelcoat protects the hull and gives it its color and shine.

When the gelcoat was originally sprayed into the hull mold, it-like any gel-took on the shape and texture of the mold surface. The ultra high gloss most new boats exhibit is due entirely to the highly polished, mirror-like surface of the mold used in the original construction of the boat.

Time and exposure eventually erode the relatively soft surface of gelcoat, leaving it dull and chalky. Fortunately, the gloss usually can be restored.

Cleaning
The first step in restoring the gloss to dull gelcoat is always a thorough cleaning. Add a cup of detergent to a gallon of water-warm water is better-and use a sponge to wash the surface with this solution. Be sure to protect your hands with rubber gloves.

If mildew is present, add a cup of household bleach to your cleaning solution. Difficult stains like fish blood and waterline scum may require the direct application of a concentrated cleaner formulated for fiberglass. Rinse the clean surface thoroughly and let it dry.

Degreasing
For dependable results from wax or polish, the gelcoat surface must be completely free of oil and grease. Detergents often fail to fully remove these contaminants from porous gelcoat. Wipe the entire surface with a rag soaked in MEK (preferred) or acetone, turning the rag often and replacing it when you run out of clean areas. Again, protect your skin with thick rubber gloves.

Wax
Keeping gelcoat coated with wax-starting when the boat is new-is the best way to prolong its life. Regularly waxed gelcoat can retain its gloss for 15 years or more. The real purpose of a coat of wax is to protect, but wax also has restorative properties if the gelcoat is not too badly weathered.

Application instructions vary among brands, but in general you apply the wax with a cloth or foam pad using a circular motion. Let the wax dry to a haze, then buff away the excess with a soft cloth, such as an old bath towel. The remaining wax fills microscopic pitting in the gelcoat and provides a new, smooth, reflective surface.

Polishing
Polish is not a coating, but rather an abrasive-like extremely fine sandpaper. Polishing removes the pitted surface rather than coating it. Use a soft cloth to apply polish to a small area at a time, rubbing with a circular motion until the surface becomes glassy. After polishing, you should apply a coat of wax to protect the surface and improve the gloss. Some polish products include wax in their formulations.

Using Rubbing Compound
If the gelcoat is weathered so badly that polish fails to restore its shine, you will need the stronger abrasives rubbing compound contains. Wax on the surface can cause the compound to cut unevenly, so first remove all wax by "sweeping" the surface in one direction-not back and forth-with rags saturated with dewax solvent or toluene.

Select a rubbing compound formulated for fiberglass and use it exactly like polish, rubbing it with a circular motion until the surface turns glassy. The gelcoat on your boat is about 10 times as thick as the paint on your car, so compound shouldn't cut all the way through it as long as you are careful not to rub in one place too long. If the gelcoat starts to look transparent, stop.

After the surface has been compounded, polish it, then coat it with wax and buff it. Providing the gelcoat has an adequate thickness-the boat might have been compounded previously-this process will restore the shine to fiberglass in almost any condition.

Do You Need an Electric Buffer?
You can wax, polish, and compound by hand, but on anything but the smallest boat, your arm is going to get very tired. An electric buffer takes much of the work out of keeping a boat shining and is less expensive-and less painful-than elbow replacement.

Electric buffers operate at relatively slow speeds, so don't try to "make do" with a polishing bonnet fitted to a disk sander or a sanding pad chucked into a drill. You will either ruin the surface or ruin the tool. A buffer with an orbital motion will leave fewer swirl marks.

Restorer
In recent years a number of products have come on the market that claim to restore the surface of the gelcoat. Restorer formulations renew the gloss in essentially the same way as wax-by providing a new smooth surface-but without the need for buffing. Results can be dramatic, but because restorers are a plastic (acrylic) coating-similar to urethane varnish-they can wear off, flake off, and occasionally discolor. Restorer kits typically include a prep wash and sometimes a polish in addition to the restorer. A specialized stripper-for removing old sealer-is also necessary.

There are variations in the recommended application, but in general it is the same as already described-clean, polish, and coat. The acrylic sealer is usually water-thin, so applying it to the hull is much easier than, say, pastewax. And it dries to hard film, so no buffing is needed. However, you do have to apply several coats-five is typical-to get a good shine. If the product you have selected doesn't include an applicator, use a sponge or a soft cloth to wipe the sealer onto the gelcoat. Drying times are short, so subsequent coats can generally be applied almost immediately.

A multicoat application can restore the shine to weathered gelcoat for up to a year, but when it is time to renew it, you will need to remove the old sealer using the special stripper supplied in the kit (or available separately). Apply five fresh coats of sealer and your boat should shine for another year.

Back to top

Gelcoat Scratch Repair

Surface scratches can be buffed out of gelcoat with polishing compound, but deep scratches must be filled. When the gelcoat surrounding a scratch is in good condition, the filler of choice is gelcoat paste, which provides both filler and finish in a single application-but not a single step. Because the surface of the cured paste will be uneven, sanding and polishing are required to smooth the repair and blend it with the rest of the hull. Except for color matching, gelcoat repairs are easy and straightforward.

Gelcoat Choices
You will find gelcoat available as both a resin and in a thicker putty form called paste. For scratch repair you want paste. Repair kits comprised of a small amount of gelcoat paste and hardener, a selection of pigments, mixing sticks, and sealing film can be purchased for less than $20. Buy a flexible plastic spreader if you don't already have one. You will also need sheets of 150-, 220-, 400-, and 600-grit wet-or-dry sandpaper. A single sheet of each will be more than ample to fair all the paste in a repair kit.

If you are repairing several scratches, add a small bottle of styrene to your list of supplies. Wiping each scratch with styrene just prior to filling it partially reactivates the old gelcoat, resulting in some chemical bonding between the old gelcoat and the new. Otherwise the bond between old and new is strictly mechanical-like a coat of paint. A mechanical bond is normally adequate, but the more extensive your repair, the more certainty you want.

Color Matching
The hardest part of a repair to the surface of a fiberglass boat is matching the color. Professionals who do gelcoat repairs daily still have difficulty getting a perfect match. Even "factory" colors don't match exactly after a boat has been in the sun for a few years.

White has the significant advantage of being fairly easy to match, and once a small repair is buffed out to a gloss, shading differences will be unnoticeable. Matching colored hulls is somewhat more challenging.

A color-sample card from your local paint store that matches your hull can provide valuable help. Ask the store clerk the formula; they custom-mix the color by adding tints to a white base. The formula may call for a half-dozen different tints, but the important ones are those specified in the largest quantities. You can use the tints in your repair kit to approximate the formula.

Always color gelcoat paste before you add the catalyst. Put exactly one ounce of paste into a mixing cup and add the tints a drop at a time. Keep track of the number of drops of each tint. When the color looks close in the cup, touch a drop of the mix onto the hull. Make needed adjustments until you are satisfied with the match-don't expect perfection-then write down the formula so you can duplicate it for the rest of the paste.

Preparing the Scratch Never try to repair a scratch by simply painting over it with gelcoat. Gelcoat resin is too thin to fill a scratch and gelcoat paste is too thick. Instead of penetrating scratches, gelcoat paste will bridge them, leaving a void in the repair. To get a permanent repair, draw the corner of a scraper or screwdriver down the scratch to open it into a wide vee.

This is the time to wipe the open scratch with styrene to reactivate the old gelcoat.

Catalyzing
The hardener for gelcoat is the same as for any polyester resin-methyl ethyl ketone peroxide, or MEKP. Gelcoat resin usually requires 1 to 2 percent of hardener by volume (follow the manufacturer's instructions). As a general rule, four drops of hardener will catalyze 1 ounce of resin at 1 percent. The mix shouldn't kick (start to harden) in less than 30 minutes. Hardening in about two hours is probably ideal. Always err on the side of too little hardener. Also be certain to stir in the hardener thoroughly; if you fail to catalyze every bit of the resin, parts of the repair will be undercured.

Spreading Gelcoat Paste
Work the gelcoat paste into the scratch with a flexible plastic spreader. Let the putty bulge a little behind the spreader; polyester resin shrinks slightly as it cures, and you're going to sand the patch anyway. Just don't let it bulge too much or you'll make extra work for yourself.

Scrape up any excess paste beyond the patch area.

Covering the Repair
Gelcoat will not fully cure in air. To seal the surface of a scratch repair, cover it with a sheet of plastic film. The kit may include sealing film. Otherwise a section of kitchen "zipper" bag works especially well because it tends to remain smooth and the gelcoat will not adhere to it. Tape one edge of the plastic to the surface just beyond the repair, then smooth the plastic onto the gelcoat and tape down the remaining sides.

Sanding and Polishing
After 24 hours, peel away the plastic. The amount of sanding required will depend on how smoothly you applied the gelcoat.

A 5 1/2-inch length of 1 x 2 makes a convenient sanding block for a scratch repair. Wrap the block with a quarter sheet of 150-grit paper, and use the edge of the block to confine your sanding to the new gelcoat. Use short strokes, taking care that the paper is sanding only the patch and not the surrounding surface. Never do this initial sanding without a block backing the paper.

When the new gelcoat is flush, put 220-grit wet-or-dry paper on your block and wet sand the repair, this time with your block flat. Use a circular motion and keep a trickle of water running on the sanding area. Feather the repair into the old gelcoat until your fingertips cannot detect a ridge. If the hull is curved, take care not to sand the repair flat.

Abandon the block and switch to 400-grit wet-or-dry paper. Wet sand the surface until the repair area has a uniform appearance. Follow this with 600-grit wet-or dry. Wear cloth garden gloves-the kind with the hard dots-to save the tips of your fingers.

Dry the area and use rubbing compound to give the gelcoat a high gloss. Swirl a soft, folded cloth over the surface of the compound to load the cloth, then rub the compound onto the repair area. Buff it with a circular motion, using heavy pressure initially, then progressively reduce the pressure until the surface becomes glassy. If the gelcoat shows swirl marks, buff them out with a very fine finishing compound.

Finish the job by giving the repair area a fresh coat of wax. If your color match is reasonably good, the repair will be virtually undetectable.

Back to top

How to Winterize Your Boat

Winterizing your boat for the majority of us is the most dreaded day of the year. Warm weather is gone and so starts the wait for spring temperatures so we can hit the water again next season. Take these protective measures to assure your boat will greet you with a happy face when warm weather welcomes you again in a few months.

Standard Winterization

1) Run a fogging solution through the boat engine while it is running to protect internal parts
2) Spray a protective anti-corrosion film on the external parts of engine
3) Drain the engine block and manifolds and fill the engine with anti-freeze
4) Drain the lower unit gear oil and refill with fresh oil (stern drives only)
5) Grease all external fillings on stern drives
6) Disconnect the battery / batteries and store somewhere warm
7) Cover your boat


Optional Winterization

1) Remove spark plugs and spray oil on cylinders, then replace spark plugs
2) Change engine oil and filter
3) Remove prop and grease prop shaft
4) Add fuel stabilizer to prevent condensation in gas tank (run engine briefly to flush stabilized gas through fuel injectors and carburetor)
5) Winterize fresh water system
6) Remove outdrive and grease U-Joint

The above winterizing tips are only a list of suggested things to do your boat that I've collected over the years. Each boat may vary as to what needs to be done to winterize it. For complete instructions please see your boat's owners manual or consult your boat mechanic.
Back to top

How to De-Winterize Your Boat

So, you have got that itching spring fever to uncover the boat and get her wet for the first time this season. There is nothing worse than being gathered at the dock with a boatload of people and you turn the key and...rrr..rrr..rrr...and nothing. It is likely this will happen if you do not take the time to do an inspection before setting out on the first trip of the season.

To avoid any embarrassment and frustration, use the following pre-launch checklist to get your boat as ready for the waterski season as you are.

Oil Check
If you did not change the engine oil when you put the boat up for the season, now is the time to do it. Make sure you change the oil filter also. Check oil in outdrive.

Battery Inspection
Reattach the cables. Make sure the terminals are not corroded. If so, wipe them clean. If your battery takes water, fill it up. A dry battery is a bad battery. (I learned that the hard way.) With a battery tester, check the volts and amps. Does it have juice? If it is charged and still no luck, it may be time to buy a new battery.

Cooling System
Hopefully you drained the cooling system if you live in a cold winter climate to prevent freezing. If so, fill 'er back up. Rinse out the strainer and check the hoses for cracks.

Fuel System
You also should have topped off the tank with gas to prevent any moisture and condensation forming in the tank and diluting the gas. Change the fuel filter. Make sure the fuel line is attached and not cracked. In the winter these hoses can become dry and brittle.

Distributor
Take the distributor cap off and clean it out. Corrosion could have occurred during the winter. Make sure all connections are restored.

Belts
Tighten the belts if needed. You should only be able to push the belt slightly down. If the belts do not fit snugly in their pulley grooves, they may be worn and in need of replacement. Belts that are not tight will wear faster because they will likely begin to slip. The alternator belt usually wears faster than the others. A sign of a worn belt is black soot somewhere in the vicinity of the pulley.

Other Things That Should Not Be Ignored
- Change the spark plugs
- Lubricate the engine with WD-40
- Check all hoses
- Check power steering / cables
- Test the bilge pump
- Replace the drain plug
- Check rudder and shafts
- Inspect the prop Test the horn
- Test the VHF radio
- Check the trim
- Inspect Personal Flotation Devices
- Check the fire extinguisher expiration date
- Make sure the anchor in on board

The above de-winterizing tips are only a list of suggested things to do your boat that I've collected over the years. Each boat may vary as to what needs to be done to de-winterize it. For complete instructions please see your boat's owners manual or consult your boat mechanic.

Back to top

These tips are provided as a reference and starting-point only.  All maintenance and repairs should be performed by someone with adequate knowledge and ability to do the task at hand.  We assume no liability for any suggestions provided within this website!

You are visitor number since 7-15-07.