300U Missing at Low Idle

MFan · May 6, 2012

300 utility, still 6 volt positive ground. New points and plugs, timing set. Runs well at high rpm, good power. When dropping back to low idle, will miss but not in a regular pattern. Idle is set around 500-550 rpm, will stay at that and not die off. Any suggestions?

504 · May 6, 2012

Idle circuit in the carb is plugged. Try Seafoam first before tearing into the carb.

Janicholson · May 6, 2012

If it just pops and flips the rain cap every few seconds it is pretty normal. I would adjust the idle mix and timing to spec, and if it is inconsistent, and as described, leave it alone. Jim

David G · May 7, 2012

I would check the valve clearance, could have one wide.

300U Missing at Low Idle

MFan

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504

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Janicholson

Well-known Member

David G

Well-known Member

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