340-6 rear carb issue

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Michael Siple

Michael Siple

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Wilmington, De.
got a rear carb dumping fuel causing problems. you can see it leaking while running @ idle making things rich & rough . my limited knowledge says float & needle ? what would you look for or check. would be nice to peck on it & have it go away but it didn't. thanks. mike.
 
Check the needle and seat for dirt and or wear...

If there is fuel coming out the vent, then there is a problem with the needle and seat mating properly, usually caused by dirt or worn seat..
 
You can do needle and seat without pulling carb out. If that doesn't fix it, check float for gas inside from leak if it is hollow brass.
 
Used to be only dirt was the issue for needle and seats. Now with fuel formulations, they love to shrink the o-ring and a leak occurs there.

Dirt
O-ring
Sunk float

Are the typical issues with overflowing carbs.
 
That's what I went by when I rebuilt all of mine last year as I t has all the info you could want. Fortunately I did not need the pro max outer plates to tune it, and it runs like a scalded dog, with outboards coming in without stumble.
 
sounds like I maybe able to remove needle & seat on car ? went to Rochester carb school bout 81yrs ago & I remember needle kinda hinged to float. how does what I need to do get done without reaching float ? maybe i'm making bigger deal of it than I should. I remember needing to have fingers on float when playing with needle & I wont be able to see or touch float without disassemble. school me.
mike
 
Michael Siple said:
sounds like I maybe able to remove needle & seat on car ? went to Rochester carb school bout 81yrs ago & I remember needle kinda hinged to float. how does what I need to do get done without reaching float ? maybe i'm making bigger deal of it than I should. I remember needing to have fingers on float when playing with needle & I wont be able to see or touch float without disassemble. school me.
mike
Click to expand...
WOW no offense but your old as dirt...you prob forgot most
 
so far so good. believe i was making a bigger deal of it than it really is. removed needle & seat & sprayed it up with wd40 wet it with a little vaseline & slipped it back in. played with float adj (have a question about that) & it runs well. lousy little spec of dirt. runs nice hot in drive foot on the brake. smoother than i can remember. My question- when reinstall needle & seat- remove float level plug & wiggle fender to drain bowl. how far in do you thread seat into carb before beginning adjustment.
 
A good place to start is when float assy screws in and the lock nut is fully threaded onto top of assy there should be about 1 thread showing above nut. That should get you close.
 
that's what I was looking for - where to start. I must have got it close. the way it runs right now i'm going to leave it be. thank you for the reply. mike
 
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