High Temp Alarm and Light Coming On

[SEAHORSE]

There are "high flow" water inlet screens available for your motor. Perhaps trying a set of those may be all that is needed on that motor. Your dealer can order them for you.

Do you have bottom paint on the hull, or are there any barnacles or any marine growths underneath the hull?

Just to check something, temporarily install clear tubing to the "blow-off" valve fittings and watch the flow. If there are millions of air bubbles, you might have found the problem.

Because the cylinder heads are lost-foam castings, there are inaccessable areas that could have a corrosion buildup which could impede the outflow of cooling water. That was more common on the 60 degree motors, but could be a cause of yours.

[Cattail]

As of today I am dead in the water. My dealer after consultaion with BRP techs are now only suggesting to try this and that. Repair cost to date is $1400 with problem still occurring. Suggestions are to remove powerhead and check gasket between head and lower unit along with the exhaust that runs by the gasket. Dealer still wants to replace powerhead but I would like to know what is causing the problem before spending big bucks. Other options are to "slap" on a pair of four strokes, again major expenses. I just can't believe that after only 500 hours of normal wear and tear (I treat the engines with care) that they are used up and need replacing.

Once again, thanks to all who have responded, but this ordeal has become very frustrating.

[SEAHORSE]

How far are you from Lewes, DE ?

[Cattail]

Only about 1 1/2 hours away. Vacation there alot. I believe a friend of mine who has an independent boat mechanic shop has talked to someone from Lewes about this problem.

[SEAHORSE]

Talk to the mechanics at Pontoon Express there, they have a great reputation according to the factory folks.

[Cattail]

Will definitely give them a call. Thanks.

[Cattail]

The latest scenario is to check for stuck pistons rings in lower starboard cylinder that may have been caused by the engine running too cool and causing a carbon build-up. The suggestion is to replace piston and rings and either hone the cylinder or try acid wash. Need to get estimate on the labor and materials on this versus purchasing new powerhead and installation.

[RUSTY63]

This is a long shot but, I have seen build up around the temp sensor pocket on the inside of the cylinder head from minerals in the water that cause the sensor to over heat and turn the light on.

Bad thing about this is there are only two ways to check it....1- replace the cylinder heads....2- have the local radiator shop boil them in the tank they use to clean radiators.

[Cattail]

I agree about a long shot, however, we have virtually eliminated anything to do with the cooling system as most parts were replaced, cleaned,and flushed.

Is it time to look at an oil problem such as not getting enough oil around the cylinders in question causing a heat-up, or maybe a fuel injector problem where too much fuel is being injected causing excessive heat?

The approach concerning the running of the engine too cool and causing a build-up will at least let us look at the cylinders. The powerhead has to come off to do this and if it looks too bad at least we are on our way of replacing the powerhead.

Again, thanks for all the input.

[SEAHORSE]

I got called yesterday to consult on a 2001 225 FICHT that would overheat above 4000 rpm even after t'stats, water pump, pressure relief valve, etc. was replaced.

I hooked up a water pressure gauge and hose and went for a ride with the dealer. About 4300 rpm the water pressure dropped to about 5 psi and the motor HOT lite came on shortly after. After checking over the motor and hooking up the computer and doing lower speed runs that did fine, I found that a slight right turn increased water pressure and hard left turn increased pressure. I had them pull the boat out of the water and found that the owner recently had a color transducer installed with a large plastic fairing block. The side of the block was only 7 12" from the boat keel centerline and the trailing edge was 34" ahead of the motor. The block was 4 1/2" deep hanging below the hull. My recommendation was to move the transducer outboard as far as possible. Installing a test wheel on the motor and letting it run up to WOT had a steady water pressure and no temperature problems.

Cattail,

Ask your dealer to hook up a test wheel, put the boat in the water and let that engine rev up to the recommended rpm. Monitor the water pressure gauge and the temps to see if the problem continues. If it runs fine, then there is a boat problem. If it still acts the same, then its in the motor.

[Cattail]

Next week we plan on addressing that there are no blockages in the water jackets along the right side of the engine. If none ,we are pulling the cylinder head to look at the scoring and see if stuck rings are the problem. If so, a decision on re-build or replace powerhead may need to be made.

[Cattail]

The continuing saga... Today we tested the waterflow on both cylinders by running water at a constant rate through the thermostat opening on the port side. Once we determined the rate to be equal ( inflow vs. outflow) we moved the hose to the starboard side and in about 2 - 3 seconds the water was overflowing. There must be a blockage.

Removed powerhead from lower unit and lodged in the starboard side hot water drain was a piece of plastic similar to the threaded insert from the thermostat cap. It appears that the hot water was not allowed to escape quick enough and backed up around the lower starboard cylinder causing the overheating.

It seems that my dealer in 3/04 replaced my thermostats and in attempting to remove the caps broke them off. Late last year we found similar pieces floating in the thermostat housing on the port side when I was having problems with overheating.

We ran water through the powerhead while it was removed and both flowed equally. We also ran water through the water drains in the lower unit and they flowed equally once the piece was removed. Ordered a new gasket for the lower unit/powerhead and maybe by Wednesday can water test and check temperatures while running with the infrared gun.

My only concern is what damage has been done to the cylinder that has some scoring on it.

Will let you know how the water test went.

[ChampioNman]

Cattail, I think we all told you there was some type of restriction in the H20 passages, although I thought you may have had a bad H20 deflector in the heads. A compression and leak down test will tell you if you have any cylinder damage. Good luck and keep us posted.

[Cattail]

That's our plan now. Water test to check cylinder temperatures after running at cruise speed. I will ask for the compression and leak down tests.

When my dealer looked at the problem in early October, he said he flushed and cleaned the water jackets as well as replacing the water deflectors. I was hoping that took care of any blockage, but we found out different.

Thanks to all for your wisdom and help!

[Cattail]

Finally some resolution. Water tested today and ran boat at 4000 rpm's for quite some distance. Mechanic tested cylinder temperatures with infrared gun while running. All cylinders ran between 125 - 140 degrees. Back at shop did leak down test. The cylinder in question showed 8 % leak down while all others showed between 4 - 6 %. Compression test showed 135 in both tops and middle and 130 in both bottoms.

Hopefully overheating problem is solved and scoring in the one cylinder must be very minimal.

As I have said before thanks to everyone who responsed with suggestions.