yamaha 25hp fourstroke leaking oil and water from head gasket

[Feltnerd]

my 2001 yamaha 25 hp four stroke is leaking water and oil from the head gasket, there is also a hint of oil in the pee stream water, This would lead me to believe that its head gasket. Is my diagnosis correct, also does anyone know the torque sequence of this motor???? also recently my water pump went out and my overheat alarm went off, I'm thinking this may have been the cause, not sure. I believe the model is F25TLRZ or something along those lines. Any help would be much appreciated. thank you

 

[GSpivey]

Re: yamaha 25hp fourstroke leaking oil and water from head gasket

I just had the same sort of thing just happen with my 2004 25 hp 4 stroke... Over heated badly one time... Turned it off as soon as the buzzer sounded... Couple of trips later it started idling bad. Ran ok at full throttle.. Found the top cylinder was getting water in it and the oil has water... Hope it is just a head gasket... Fingers crossed..

my 2001 yamaha 25 hp four stroke is leaking water and oil from the head gasket, there is also a hint of oil in the pee stream water, This would lead me to believe that its head gasket. Is my diagnosis correct, also does anyone know the torque sequence of this motor???? also recently my water pump went out and my overheat alarm went off, I'm thinking this may have been the cause, not sure. I believe the model is F25TLRZ or something along those lines. Any help would be much appreciated. thank you

 

[sipic]

Re: yamaha 25hp fourstroke leaking oil and water from head gasket

Hi Feltnerd,

Can I ask how you got on with your head repair? I've just bought a 2002 25HP high thrust Yamaha and it's pretty clear that the head gasket has gone. The engine was a bargain so I'm going to pull the head off and have a look at the damage. I'd be interested in finding out about your experiences? Yamaha aren't too helpful with the service manuals so it looks like I'll need to rely on community help so any advice would also be gratefully received.

All the best.

 

[GSpivey]

Re: yamaha 25hp fourstroke leaking oil and water from head gasket

I ended up buying a used long block with a head and just used the head.. Never could find the leak in the head though... Btw I would be willing to sell the block and The bad head... I think the Problem was a shredded water impeller sent into block causing cooling issues... Thinking of trying to add a temp gauge...

 

[sipic]

Re: yamaha 25hp fourstroke leaking oil and water from head gasket

Thank you for the feedback GS. I've pulled the head off and whilst there's some discoloration of the facing surfaces I can't see any sign of an obvious blow. I've cleaned off the faces and reassembled the engine with a new gasket and I'm going to run the engine for this season and see what happens. The cooling jacket had a few foreign bodies in it but I think these just get pumped through as there wasn't any other signs of damage.

I've been told that the base gasket may be the source of the water as it's thinner and exhaust, water and oil are all pumped through it. That may be my next stop if the water re-appears.

 

[GSpivey]

Re: yamaha 25hp fourstroke leaking oil and water from head gasket

I also could not find a definite breach. I scraped and sanded the surfaces and checked them with a machinist straight edge and feeler gauges.. I agree try a head gasket first.. The bottom power head gasket would be a pain but is another possibility... Mine was a problem in the head and could never see it..