40 h.p. yamaha outboard. maybe year 88<br /><br /> after running i inspect sparkplugs and found water particles. I replaced head gasket and exhaust cover caskets. Still can't cure the problem<br /><br /> norfin
hello<br /> did you surface the cyl. head? or at least test it for warpage? did you inspect the exhaust divider plate for corrosion pinholes? sometimes a broken reed will cause water in the cyl. look for any milky discharge from any carb throat too as this would point to a reed. <br /> good luck and keep posting
Rodbolt,<br /><br /> I have tested the possibilities that you adviced. There are still traces of water in two plugs. Its a 2 cyl. outboard. Any other sources of leak? I cant afford a new block.<br /><br /> norfin
Hello<br /> there are limited spots for water intrusion. it can come in with the fuel mix from water in the carbs. it can come in as a spray from the exhaust divider plate. it can enter from a bad cylinder head casting or gasket seal. and it can be drawn back into the engine from the pressure pulses created by a defective reed. try to find an automotive shop or marine shop with a leak down tester. lock the flywheel at the TDC for the cylinder your testing. apply 100 psi air pressuere and try to see where it leaks. listen to where the air is hissing from it is sometimes easiest to place the motor in the water to seal off the lower and tstat discharge ports.then tape off the idle relief ports then remove the tstat and listen for air. if no air the cylinderhead/cylheadgasket is sealing. its a lot of work but about the only way. if you run it with water spraying in the cylinders a block wont be nessasary. good luck and keep posting