mercury mariner carb trouble.

[funbilly]

I have a early 90's mariner 40 hp 4cyl. 2 stroke. Runs fine, when I shut the motor off it leaks fuel. I have determined the problem is the seat and the needle at the inlet valve. The problem is the seat is pressed in not screwd in. Heard of a fix involving drilling out the seat and removing it with a screw, But can't find a seat anywhere. The motor is made by mercury And they have been no help! Any info would be great even if its a lead on new or rebuilt carbs for it. Thanks

[broken_line]

ahhh in the 3 snowmobiles, 3 boat motors and countless 2 stroke go cart motors. ive never had to replace the seat. i would say your float could be off adjusted or there is something holding it from closing. when did you last clean the carbs? might be a good place to start if you havent in a year.

[boatfixer]

What is the serial number of the engine?

[funbilly]

The serial number is OC295476 I have cleaned the whole carb and replaced the needles it barely holds when I check it with the vaccum guage. Even had a second opinion and he said I might be screwed because they are pressed in.

[boatfixer]

Just one or both carbs are leaking? Is the float bowl vent clear? If it is plugged, the main jet becomes the vent and gas can leak through there. Are you sure the float level is correct?

[funbilly]

Yep I,ve gone through every thing twice and some 3 times. What I've done so far has almost completely stopped the fuel leak. So I'm thinking I'll start saving up for a new motor or boat and just keep an eye on the problem.

[raymondk]

i have the same motor and i thought that the needle seats were bad bought new needles made the problem worse put the old ones back it always seamed to run good but i always had gas leaking when i pulled it down the road . finally I figured it out it was the fitting that hooked up to the motor which i replaced the year before but were aftermarket one that if you compared them they were diferent from now on i will only use oem fittings it took care of my leak the whole time I thought the problems were in the carbs