99 OX66 S250TURX water in cylinders

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PBJohn

Seaman
Joined
Nov 26, 2008
Messages
52
My latest finding appears to be water in cylinder #3 and #4. This originally started at #4 and has now gone to both. Compression is 105 on all cylinders. I can get about 4 hours of run time or 75 gallons of fuel before I start misfiring. Now for some questions. Is there a way to pressurize the water side? Would a cylinder leak down test work on a two stroke? What prevents water from entering the exhaust side? I attached a picture of the plugs that just came out. If anyone can provide some guidence it would be appreciated. Thanks
 

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PBJohn

Seaman
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Nov 26, 2008
Messages
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Re: 99 OX66 S250TURX water in cylinders

Can't imagine what it could be . Intake and xxhaust sides were opened up and nothing was found. Had the cylinder heads off twice. Anyone have any suggestions?
 
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Tommy in FLL

Seaman Apprentice
Joined
Apr 10, 2009
Messages
44
Re: 99 OX66 S250TURX water in cylinders

Could be a warped head. Once it heats up, it warps enough to allow water to get past the head gasket and into the combustion chambers. Did you measure it with a straight-edge when you had it off?

My C85 Yamaha has a problem with overheating and exhaust comes out of the thermostat port if I run it with the t-stat and its cover removed. I changed the head gasket, but didn't check the head for warps....

:mad:

My bad...
 
P

PBJohn

Seaman
Joined
Nov 26, 2008
Messages
52
Re: 99 OX66 S250TURX water in cylinders

Yes They checked out good. I am not having any overheat issues. As a matter of fact it runs flawless until I manage to foul out the plugs. Being from the automotive side maybe I'm reading the plugs wrong. This is saltwater use two stroke so I'm not even sure if this is what saltwater looks like on a plug.
 
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