1947 Scott Atwater - 3.6 hp - Won't Idle

Hmkidd

Recruit
Joined
Feb 27, 2016
Messages
1
Hello all,
I'm restoring an old 3.6 hp Scott Atwater and I'm having trouble with getting it to idle. It starts just fine, and runs great at full speed, but when I ease up on the throttle it will stop running. Adjusting the high speed needle seems to work, however the adjusting the idle needle does nothing. Anyone have any ideas as to why it won't idle or run at low speeds?

Thanks
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Just aft of the slow speed needle there is what appears to be a brass screw going in at an angle. That actually is the idle tube. It meters the fuel going into the idle circuit. The holes in it are very small and easy to get plugged up. Short story is remove it and clean it.

BTW, the idle mixture needle works backwards from "normal" carburetors. Screwing it in makes the mixture richer. Normal opening is about 3/4 turn, rarely any more than that.

Those motors should idle excellently. If it doesn't, something is wrong.
 
Top