by Bob Teague

Question Of The Month:

INADEQUATE BOAT LIFT
Question: I have some questions concerning how to store a boat correctly on a boat lift in warm and humid Florida.

I have a 2007 Fountain 35 Lightning and want to make sure that I store this boat optimally when the boat is on the lift. I have seen many different ways to make the bunks on the lift cradle. My cradle has only four bunks total that are 5 1/2 inches wide and 36 inches long. Two are mounted on each cross arm. Is this enough support for the boat?

Besides flushing the engine and washing the boat, what else should be done after running in saltwater?

Atle M. Staff
Pompano Beach, Fla.

Answer: Your lift is not a correct design for a performance boat. It is important to provide as much support for your hull as possible while it is on the lift. A fore and aft V-bunk should be present to support the keel, which is one of the strongest parts of the hull. Other bunks should extend past the transom slightly to minimize the possibility of creating a hook in the bottom. If you do not support the boat correctly, it is likely that you will start noticing diminishing performance.

Saltwater is abusive to your boat. You must take special care to flush the engines and drives. Do not wash the engines off in the boat. If you do get salt spray on them, clean them carefully.

DIESEL-POWERED FAS3TECH
Question: I have a 1998 Formula 382 FAS3Tech, which I have repowered with the new MerCruiser diesel engines. Currently I am running 63 mph at 3,800 rpm, which is the maximum rpm for the engines.

I am using 30"-pitch Mercury Maximus propellers spinning outward. Would the lab-finished 32"-pitch Maximus propellers give me the same rpm and more speed?

Would spinning the propellers inward increase the speed even more? The boat runs great with a cruising speed of about 55 mph. The fuel consumption is very low, but it would be fun to have a little more top-end speed.

Gorm Oye
Oslo, Norway

Answer: The Mercury Maximus propellers are a good choice for your diesel-powered 382 FAS3Tech because they are very efficient.

You will probably gain some speed by going up to 32"-pitch lab-finished Maximus propellers. If you are currently running the full 15 5/8-inch diameter, I would stick to it with the higher-pitch lab-finished version. This way, you will maintain the efficiency while gaining the benefits of the better propeller.

The Formula 382 FAS3Techs were one of the popular hulls in the APBA Factory 2 class. In fact, I raced one for a year. We always turned our propellers inward for maximum speed. So, I am guessing that it will be faster if you turn the propellers in. The boat should be easier to dock and may come on plane faster with the propellers turning out. You will just have to try it to find out which way you like best.

HP500 TO 500EFI CONVERSION
Question: Thanks for your articles! They are very informative and are a big help to all of us who read them. My questions for you concern my new-to-me 1996 Eliminator Daytona with a Mercury Racing HP500 engine. We often boat at Arizona's Lake Havasu (about 500 feet above sea level) and Lake Powell (about 3,600 feet above sea level).

Temperature variations between the two locations are as much as 40 degrees. So, you can see why I am determined to install an EFI system on my engine. There are plenty of used systems available on the market. Will the new style HP500EFI or HP525EFI systems work with my 1996 502-cubic-inch carbureted HP500?

At the same time that I'm into the engine, I might as well do the valvetrain. Do you have any suggestions on which hydraulic roller cam and ignition setup to buy? About 60 extra horsepower would be nice, but my main goal is fuel economy and reliability.

David Hastings
Anaheim Hills, Calif.

Answer: There are many similarities between your carbureted HP500 and the next generation HP500EFI. The basic differences are the camshaft, exhaust system, induction system, electronics and ignition. It would be easier to convert your engine to the HP500EFI-style engine than it would be to convert it to the HP525EFI. The 525-hp engine does use a similar bottom end, but has a proprietary aluminum cylinder head made for Mercury by Edelbrock. The 500EFI uses the same raw-water cooling system as your current engine. The HP525EFI uses a closed cooling system, which you currently don't have.

The HP500EFI uses a Crane Cams Part No. 169621 hydraulic roller camshaft that is slightly "larger" than the carbureted version. The roller lifters and valvetrain are the same in both motors. Earlier HP500 carbureted motors used Crane Cams valve springs, which did have a share of breakage problems. Later versions and all HP500EFI engines were equipped with Competition Cams Part No. 929 valve springs, which have a good reliability record.

The Comp Cams spring requires the use of a different retainer, which is a Crane Cams Part No. 99961. This valve spring/retainer combination uses a Crane Cams Part No. 99098 lock and is installed at 1.880 inches for best performance.

You should get rid of your GIL exhaust system and install the CMI Elbow Top headers that are similar to those used on the HP500EFI. This is the exhaust system that the EFI system is calibrated for. Also, using the CMI headers will resolve your likely exhaust water reversion problems.

The polished version is CMI Part No. 13005, or if you want to save a little money, you can opt for the satin primary version (Part No. 13055). I also recommend that you upgrade to the CMI stainless-steel distribution tubes that will make your exhaust water plumbing easier and more sanitary.

The best way to make the conversion is to purchase a complete take-off HP500EFI induction system with all of the wiring harnesses and ignition system. You also will have to use the Delco-style electronic distributor that is used with the HP500EFI system. The "charging harness" is different. Yours can be modified if you know what you are doing. It is easier to change to the HP500EFI harness. The MEFI 3 ECU is housed in the box attached to the rear of the right cylinder head along with the starter slave solenoid, circuit breaker and relays.

Your existing V-belt system for the accessories can be used even though the production HP500EFI used a serpentine belt system. You will need to modify the HP500EFI wire harness to connect to your existing Mando alternator. The HP500EFI harness uses the same 10-pin connector to the boat harness as your existing setup (later model HP525EFI engines use a 14-pin connector that is not compatible with your boat harness).

I think that converting your carbureted HP500 engine to the HP500EFI would be a worthwhile upgrade for your boat. That being said, I don't think that any EFI system is totally capable of compensating for different altitudes and weather conditions. The EFI system is capable of adjusting to varying barometric pressures, but that doesn't mean you will have the same power at Lake Powell as you do at Lake Havasu. I do believe that the low and midrange fuel economy will be better with the EFI system. The wide-open-throttle fuel usage will be about the same.

YOU'LL NEVER BE SORRY
Question: I have a question for you. I am interested in buying a Baja 26-foot Outlaw. I read in Powerboat that you have done two evaluations for this boat, one that was powered with a Mercury Racing HP525EFI and the other with a MerCruiser 496 Mag HO. I was just curious what the difference was between the 496 Mag HO and the HP525EFI, and whether spending the extra money is justified?

Rob Bickardt
Livingston, N.J.

Answer: On a regular basis, I hear from boaters with larger single-engine V-bottoms powered by MerCruiser 496 Mags and HOs. Their most common remark is that they wish they had more power. This is especially the case after they have gotten used to their boat.

So, I would definitely go with the Mercury Racing HP525EFI over the production 496 offerings. The HP525EFI is a "scratch-built" motor that is assembled at Mercury Racing as opposed to the 496 which is a marinized GM-built engine. The 496s have pretty good bottom-end power (sometimes better than the HP525EFI depending on the boat). But the HP525EFI will be better in all other respects.

If you are thinking about resale value, I think you'll get all of your money back on the upgrade down the road when you decide to buy a new boat.

FLAME ARRESTOR UPGRADE
Question: I have a 1999 Crownline 266 CCR with a 7.4 MPI engine and CORSA switchable exhaust. What do you think of using an oiled-type air intake spark arrestor/filter with a fuel-injected engine?

I have used these type of air filters on my cars and have found that sometimes the MAF sensors get "dirty" with oil from the filter element. What do you think of their effectiveness? The idea of being able to clean it periodically and increasing airflow seems to be a concept that makes sense for a boat.

Eric Vreeland
Skaneateles, N.Y.

Answer: There are aftermarket performance flame arrestors available for your engine that do flow better and use the oiled-type element. Your 7.4 MPI engine does not have the same type of sensors as your car engine. Your engine uses a manifold air temperature sensor (MAT), and is equipped with a manifold air pressure sensor (MAP). Neither would be affected by the minute amount of element oil that may enter the engine past the throttle body.

Mercury Racing equipped the HP500EFI with a K&N-style flame arrestor. The HP525EFIs also use something similar. Ilmor Marine also uses a K&N element for its engines. I am sure that if it were a problem, these reputable engine companies would not be using them.

A traditional flame arrestor is not really an air filter at all. A flame arrestor's primary function is to suppress a fire that might occur as a result of an engine backfire. Usually boats are not operated in a dirty or dusty environment. The water environment is clean. The boat creates most of the foreign matter that can enter the engine through the induction system. New boats sometimes have a lot of fiberglass dust. Fiber from boat carpet also can be ingested by the engine. For that reason, a flame arrestor that also is a filter offers a little more protection for your engine.

If you decide to upgrade your flame arrestor to an aftermarket one that uses a K&N-style filter element, make sure it's designed and approved for marine use. You can't go wrong if the flame arrestor is approved by the U.S. Coast Guard.

WHERE IS THE TEMP SENDER?
Question: I have a 4.3-liter MerCruiser engine in a 1996 Maxum. The temperature gauge no longer works. I am thinking it may just be a loose connection. Where is the temperature gauge sensor located? Do you have any idea of what color the wire is that connects to it?

Jean Champagne
St. Paul, Alberta

Answer: The temperature sender for your water temperature gauge is located at the front of the intake manifold, usually screwed into the thermostat housing assembly. The standard wire color for the water temperature gauge sender is light brown or beige with no tracer stripe. The beige wire with a blue tracer stripe is for the warning system.

FIX THE CAUSE, NOT THE EFFECT
Question: I have a 2001 Eliminator Daytona with twin HP500s. It has remote seawater pickups in the sponsons under each motor.

During the five years I have owned the boat, I've replaced the water pump at least three times a year. All the pumps have been on the starboard motor except one. Of course, the starboard motor's pump is hard to get to. Last spring, after replacing the starboard pump, I couldn't get any water flow. I took apart the feed line hose to the sea strainer and found "just the right size" clamshell jammed in the hose. I think it would open like a valve most times, then pivot closed, shut off the water flow and cause damage to the water pump. The shell may have been in the hose for a number of years.

In addition, many times I have damaged a pump when taking the boat out of the water. When the boat is on the trailer, the seawater pickup sits atop a support slat and is covered. I imagine the slat needs to extend beyond the end of the hull for support so I'm afraid to cut it short. Last week, the starboard pump again went out as I was loading the boat on the trailer. I'm getting tired of replacing it.

Are there any alternatives to the stock pump? Is there one that can be run dry without damaging it? Are there any electric pump options that I could relocate in a place that is more accessible?

Jerry Frandsen
Moab, Utah

Answer: Your basic problem is that you are running your raw-water pumps without adequate (if any) water. When you burn up an impeller, the heat created can also damage the wear plates and the pump housing. It is possible that just replacing an impeller is not enough, which explains why the pump would not draw water after it was repaired. It is important for the rubber impeller to seal on the ends against the wear plates and housing (one-piece housing). If a seal is not created, air can pass by the end of the impeller, which prevents the pump from drawing water.

Fix your trailer. This is your primary problem. You can't continue to have your water pickups sitting on your trailer bunks. If you want to run your boat on the trailer, and have no other way of attaching a garden hose, you need access to the pickups. It is true that your trailer should fully support your boat in order to prevent a hook from forming in your sponsons.

You'll probably need to add another cross member to the trailer in the rear in order to support another bunk stanchion. By doing this, you can have a break in the bunk at the location where the water pickup is in the sponson. Then you will have a short section of bunk in the trailer aft of the pickup. Many trailers are built with a break in the bunks for using travel lift slings. The concept for your trailer will be similar. The bottom line is that this modification can be done for a lot less than the number of water pumps you have purchased. And you will be fixing the cause, instead of continually fixing the effect.