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Yesterday, while giving my 89' 150 proV a shock treatment, I noticed that I had water squirting out the back of the motor in about 4 different places.....all between the two lowest cylinders. The motor still runs, but I've lost top end speed. It looks like I'll have to replace a couple of gaskets on the back side of the motor. The outside plate has 29 bolts that are numbered. Also it says "torque 0.8 kgm." on the outside plate. Will replacing the gaskets on these plates get me back the rpms I've lost on the top end or is this water leak a sign of bigger problems???
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sounds like your water jackets are leaking, while youre at it, i would suggest doing your head gaskets and thermostats to be on the safe side. the power loss may be te head gasket, look at plugs, see if they are rusty in color.if it was salt water, rinse all well ! -
renegade,
I agree with JB - replace the head gaskets along with the exhaust plate gaskets at the same time.
I believe there are sacrificial anodes pressed into the cylinder block just under the heads - you need to replace them while the heads are off.
Also, you might as well go with the new mushroom style pressure control valve (poppit) while you are at it.
Inspect those heads carefully. If there is any mineral buildup in the water jackets, clean 'em out.
Instead of replacing the 'stats, try just testing them in a pan of heated water and thermometer - should be fully open at 140 degrees f. - approx 0.120 inches.
Be sure and torque all bolts according to Yamaha shop manual.
Good luck [img]smile.gif[/img] ,
Ken KComment
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Okay, let me see if I've got this straight. For parts I'll need to order 2 exhaust gaskets, 2 head cover gaskets, 8 anodes, and a pressure control valve. Did I miss anything??Comment
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renegade,
Looking at the diagram of your motor in the online catalog above, I would say 4 head gaskets, 2 exhaust cover gaskets, two thermostat cover gaskets, and one PCV gasket - along with the other items you mentioned.
Boats.net, sponsor of this forum, is a great source for parts [img]smile.gif[/img] ,
Ken KComment
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Ken, would all the gaskets be included in the powerhead gasket kit (listed in repair kit 1.) Then there would still be the 8 anodes and pcv valve. My motor is mounted to a 89' 279 v Stratus. My top end is about 49 mph. Last fall it was 55mph. I just put a 4 inch manual jack plate on which got me back up to 55-56 mph for a while but prior to changing plugs a week ago it had dropped down to 38 mph. The shock treatment didn't improve performance much more than just changing plugs. I talked to the guy that owned the boat about 4 years ago and he said it originally topped out at 65 and then slowly dropped in the couple of years he owned it. He said a couple of plugs kept fouling out so he had the engine rebuilt just before he sold it to the guy I bought it from. He thought waxing the hull would pick up some speed......I'm not sure that would make that much difference. Hopefully, the problems will be fixed with the new gaskets. Thanks for all the help. If you think there might be other problems I should look for, please let me know. Thanks a bunch.Comment
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