40johson 1987 seems to be blowin out carb.

[rogerpbarlow]

i do a little work on 4 strokes
the carbs should never have back pressure bfore sucktion. could the valve be stuck? the motor runns terrible trys to clear up but only at high rpms

 

[ONERCBOATER]

Re: 40johson 1987 seems to be blowin out carb.

1st try a richer mixture... aka more fuel at idle... perhaps lean sneezes. possible dirty carb....
2nd may be reeds... something could be stopping them from closing,,,, or perhaps a broken leaf...

I would open the idle mixture and see if this fixes your issue, if not time to look closer.

Sean

 

[boobie]

Re: 40johson 1987 seems to be blowin out carb.

Is fuel blowing out both carbs or just one??

 

[rogerpbarlow]

Re: 40johson 1987 seems to be blowin out carb.

both . if it is the reed valves how do i check them. can you see them behind the carb

 

[AlTn]

Re: 40johson 1987 seems to be blowin out carb.

go to marineengine.com...they'll have diagrams of your motor...all you'll need is the year and hp...model no. when you find the lists...easy to use site..yes, the reed block is behind the carb

 

[boobie]

Re: 40johson 1987 seems to be blowin out carb.

Take the carbs off and with small wand lite you can look right at them.