Leaking ADA O-ring?

[rossthaboss11]

The other day i noticed one of my pissers sputtering so i went back in figuring i have a blown O-ring in the head. The ski ran fantastic and the engine didn't seem any hotter than normal. The water from the sputtering pisser comes directly off the head and it did seem a little hotter though. The other pisser which comes from the head through the b-pipe mid section to the flow valve/stinger and Tee's off there is pushing water normally. I checked compression and it's where it's always been at 160/164. I have dual cooling and a B-pipe on my 850cc.

Could compression still be that good but cause this condition? The head hasn't been pulled in years so it wouldn't be surprising if an O-ring started to go. Maybe i caught it very very early. Let me know your thoughts.

 

[Big Kahuna]

If pissers are sputtering, I would say outer oring going and it is sucking air, spraying water out in a fine mist, any number of things, could be the compression orings also....... either way, just swap orings.

 

[kevbo]

The O-ring doesn't seal compression gasses, It seals water away from the steel liner. Otherwise there would be terrible corrosion at the edge of the liner. You may have to resurface the deck and/or place a shim under the domes.

 

[rossthaboss11]

I would think compression O-ring as well. There's no spray coming from the head when i run it on the hose. It's just a little strange to me it runs great and has normal compression. I guess there is a lot more force inside that engine when it's running versus a compression check so perhaps it's on the fine line of holding or not.

I don't prefer using shims under the domes. This helps for the moment but you will need more shims soon enough and eventually you damage the head shell permanently.

 

[kevbo]

Yamahas "permanent mold" cylinder design does not work too well without a crushable gasket. ADA should have known better and provided some kind of gasket. The lack of clamping force and water flow control indicate poor design.

 

[rossthaboss11]

SOLVED: Replaced all the ADA O-rings and she's good to go. There was a small break in one of the dome/cylinder O-rings.