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318 Idle slowly drops off to stall

G

gary_torello

New member
"Hi All!

My stbd 318 motor

"Hi All!

My stbd 318 motor with a newly rebuily carb doesn't seem to want to hold an idle lately. Here's what happens:

Idle down to about 1000 RPM and it will slowly drift downward until it stalls out. Makes docking real fun. If I keep that motor above 1500-1600 RPM I'm ok, but can't do anything less than that.

any ideas?


TIA!

Gary
http://www.qgm.com/gary/carpathia"
 
"Idle RPMs, in gear, tied to t

"Idle RPMs, in gear, tied to the dock, should be 650. all day long.
check your tune up details.
check your filters.
Typical low end roughness is too much spark advance or bad plugs."
 
"hmm.. no roughness.. just slo

"hmm.. no roughness.. just slowly declines to way below 650.. then of course cuts out. Last RPM I usually see is around 400. If I catch it to bring it back up.. have to goose it above 1500. If I bring it down lower, same cycle.

Was tuned up about 6 weeks ago.. will check plugs.. maybe the gas filter?"
 
"How old are the gas lines, if

"How old are the gas lines, if there are any cracks the fuel lines your fuel pump may not be able to hold the prime at lower rpms. Also check to make sure the check valve coming out of the fuel tank into your fuel line is not stuck or dirty. Experienced this problem last year."
 
"Sounds like the carb is flood

"Sounds like the carb is flooding. Try this to find out: With the motor at idle (best as you cna get it) and fully warmed up, turn the idle screws all the way in. If the motor picks up speed and/ or doesn't stall, it's flooding.

Jeff"
 
"ok- changed the fuel filter/

"ok- changed the fuel filter/ water sep.. (didn't look bad) - no real improvement. Turned the idle screw out 1/2 turn, which raised the idle speed.. lowered the idle back to about 800.. worked great. Idles about 800 or so- drop it into gear and it'll hold 650 against a load.

Thanks!"
 
Thank you for coming back to l

Thank you for coming back to let us know the solution.
 
no problem! and after re-read

no problem! and after re-reading my resolution post.. just to clarify: I turned out the LOW SPEED JET screw 1/2 turn.. and then reduced the idle using the IDLE ADJUSTMENT screw at the linkage.
 
I think you have to go thru th

I think you have to go thru that sequence a few times to get your mixure right.
 
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