Do any of these apply to your outdrive?

Need to remove White Chalky Deposits from the top of your drive:

The white chalky deposits mean 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 sign 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, its 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.

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. 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. It loses the ability to lubricate the components inside the drive, causing them to freeze and destroy the inside of the drive. It is commonly referred to as “the drive grenading”.

The unexplained need to keep topping off your drive oil reservoir bottle, is caused when the oil is overheated to a point were it is expanding and causing more pressure than the drive seals can handle. The factory pressure tests their drives by pumping air into them until they reach 15 lbs. of pressure. If the seals hold the pressure for a certain length of time, then the drive is considered good. The problem arises if the drive oil expands under heat to a point where it causes more than 15 lbs. of pressure. The drive oil is pushed by the seals until the pressure drops under 15 lbs. or until the drive oil is cooled by submersing it in water. This is the point were the drive is calling on the drive oil reservoir bottle to refill the drive. This problem is commonly referred to as “the mysterious drive oil disappearance”. No oil appears in the bilge, anywhere on the drive or transom, or as an oil slick in the water when the boat is docked. After inspecting the bilge and the outside of the drive for the presents of drive oil, the next thing that a Mercruiser Technician will do is to pressure test the drive, only to find that it passes the 15 lb. leak test. Now he is stumped and can do nothing to help you other than say that it’s up to you to keep the reservoir full at all times.

Other sign 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, its 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.

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. 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. It loses the ability to lubricate the components inside the drive, causing them to freeze and destroy the inside of the drive. It is commonly referred to as “the drive grenading”.

The Drive Oil Reservoir Bottle overflows because the drive oil has overheated to a point were it is expanding. Because it is a sealed system, it has no where to go except the reservoir bottle. The design of the reservoir bottle is to receive a normal amount of oil under normal circumstances. If the drive oil becomes overheated, it expands more than the amount meant for the bottle to handle and it overflows.

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. 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. It loses the ability to lubricate the components inside the drive, causing them to freeze and destroy the inside of the drive. It is commonly referred to as “the drive grenading”.

The price of a drive shower is cheap insurance. Unfortunately, many of my customers chose not to buy a shower until after they blew their drives. If the drive is susceptible to overheating the oil inside, than a shower would most likely stop the drive from blowing. Even if you have a bad seal that is allowing water into the drive; a drive with a cooler on it will run a lot longer with little or no lubricant, than a drive without any kind of cooling. It just may be enough time to get you back to the dock or your trailer.

The Simrek Multiport Drive Shower system comes with a built in water filtration system.

A stern drive cooling system will not be of much value to you if it plugs up with the debris that is normally found the water. How do you know if your drive shower is plugged? Are you willing to hang over the back of your boat while it is under way to make sure that it’s still working? How are you going to remove the twig that is stuck in one of the bends near the top? What about the growing problem with fresh water Zebra Muscles? These are all serious questions that you should be asking when it comes time to select a drive cooling system.

To solve this problem, we decided to add a pin to the entrance of the pick-up ports which would divide the tube in half. We also designed our dump ports to be larger than ½ of the tubing diameter, so anything that can get past the pins will flow out the dump ports. While designing our system, we experimented with incorporating a larger number of smaller ‘nozzle like’ dump ports. We also tried slots instead of holes, to give the dump-ports more of a fanning pattern. Both of these concepts led to the system plugging up with debris. Even seaweed had becoming a serious problem with these dump-port configurations. With the proper balance between efficiency and reliability, our Multiport Drive Showers with the new Patented “Max System”, will out perform any drive cooler on the market, for years to come.

The pick-up ports on all of the other drive cooler systems are mounted through the anticavitation plate very close to the top and back side of the propeller. Sometimes at lower speeds, having the pick-up ports close to the back of the propeller can allow it to draw air down the tubes and into the prop stream causing aeration of the water and the propeller to cavitate. Our new Max System locates the two pick-up ports outboard of the anti-cavitation plate away from and in front of the propeller.

Unless you have opened through hull exhaust, what you are seeing is not exhaust, its 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. or at least one full year.