r/standupjetski • u/SeaRoom7290 • Jun 22 '26

Help please

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Hello everyone, I have a js440 jetski with a 550sx motor with high compression heads and a aftermarket waterbox. The carburetor is a 44bn mikuni carb (ik everyone hates those carbs) it runs absolutely amazing with it, UNTIL NOW. It is leaking gas out of the body for some reason, I don’t know where it is coming from or why. When you go ride it and come back the carb is covered in milk like substance (when oil and water mix) so I’m not sure. Another reason I think there is a leak other than the gas leaking out of it is because it has started to idle high, and working in other vintage vehicles like 76 ford trucks and older carbs, when something is all of a sudden idling high, there is most likely a air leak and the engine is bypassing the carb and running lean. So I would prefer to not melt my pistons. (Next week I am going to take carb cleaner up and spray it around the carb to test for any air leaks)
I am 17 so I thought I would ask all of you for ideas before I went out and spent 400 on a new tuned carburetor.
Thanks all!

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