Will not Idle

[SEEN-NC]

1990-sn 351 carb.
Had the boat 6 seasons now, always garage keep...
Always stored for winter with stay built and carb fog…
This season, we started leaving the boat in the water...
Changes the plugs, rotor cap and button,
Carb. Cleaner in tank, carb.
Cleaner in carb while running...
Changed water fuel filter...
Still will not idle.. can run all rpms after 900
Anything below 900rpm will stall out…
Fresh water lake…
What is left before rebuilding the carb??????

[Rick]

RE: Will not Idle

Check the choke. with the spark arrestor off start the engine. Is the choke opening and closing os stuck open. I dont know if is mechanical or vacumn but I'll bet it is stuck open.

[SEEN-NC]

RE: Will not Idle

I think it is electronic..(mechanical)
when the engine is hot is the choke still a factor during starting...
Should the choke be closed every time you start it?
thanks

[nms1991]

RE: Will not Idle

Sounds like a problem in the idle circuitry in the carb or a possible vacume leak in the intake manifold. Try retorquing the intake manifold to 25 lb ft first, then if that does not cure it then try adjusting the idle mixture screws out a little at a time. If that does not cure any thing then more than likly you will have to rebuild the carb.