Engine knock when in water

[dawgslife]

I just purchased a 97 Daytona 770 in perfect working condition I was told. I runs fine on the trailer when I fire it up for a few seconds without wate. When I hook the water up is sounds like it has a knock and all kinds of nasty brown oily crap comes out of the exhaust. I this normal? I'm thinking head gasket. Has 125 psi in both cylinders.

I put it in the water, kept it on the trailer and reved it up. Still had the knock. Would only run at wot for a few seconds. The only way to keep it running at high speed is to apply choke. Can't find a carb rebuild kit. Any suggestions?

Any help would be appreciated.

[jhabeck]

Re: Engine knock when in water

I'd take a good look at the spark plugs and see what story they are telling. Last time I had a 2 stroke that would only run with it choked (richening it up) a seized engine followed shortly thereafter. The knock may be already that at the lower end. The difference with it in the water and out, is the engine is "loaded" in the water, revealing a worn rod, wrist pin, et cetera..

Thats my best guess without being there..


SBT sells the carb rebuild kits...but I think you've got other things going on.

[dawgslife]

Re: Engine knock when in water

Thanks for the info, makes alot of sense. I pulled the spark plugs and they were very clean. Pulled the head and it was clean as well as the pistons. Ordered new head gasket and will hope for the best. Pulled the carbs and was suprised to see they were already rebuilt. The initial settings were way off. Hopefully that was part of the problem.
Thanks Again!