Low idle hunting / surging

Dodgeit

Member
Finally have the 'ol 711 running after a freshening up of the engine. Sleeves, Pistons and rings. Along with a valve job.

She purrs like a content cat @ 800 rpms or higher. Just below 800 and she wants to hunt. Much below 700 and she will not stay running. Not too worried about that, since the rings haven't had a chance to seal yet.

Just wondering about the hunting? No amount of adjust to the carb (idle rpm adj. screw or idle mixture screw) seems to make a difference.
 
mark your current timing ,, then tinker with timing, after warmed up. make sure points are set rite .. and valves ,... new engine will need a little run in..after a few hours run , reset your valves andretorque heads WHILE WARM
 
Does choking it help or hurt the surging?? If it helps then the idle screw needs to be screw in more since it works back wards of the main jet as in in to make richer out to make leaner. If the adjustment does nothing then good chance the idle circuit of the carb is clogged up
 
(quoted from post at 12:35:02 02/04/13) Does choking it help or hurt the surging?? If it helps then the idle screw needs to be screw in more since it works back wards of the main jet as in in to make richer out to make leaner. If the adjustment does nothing then good chance the idle circuit of the carb is clogged up

Thanks old. I was going the wrong way with the idle circuit screw.
 
That is why I said something. Few people know that you open up the idle adjustment for more air instead of more fuel so they play with things and get it wrong. So just remember 99% if the idle screws are out for lean in for rich
 
Set your governor to carburetor rod. With engine off and throttle wide open, need to adjust the governor rod for 1/16 inch from wide open stop.

Gene
 
(quoted from post at 15:17:07 02/04/13) Set your governor to carburetor rod. With engine off and throttle wide open, need to adjust the governor rod for 1/16 inch from wide open stop.

Gene

Gene, thanks for that suggestion. This is a pulling tractor, so the rpms are a bit higher than stock. Is the adjustment still the same at 2200 rpms as it is at 1650? Or set it at 1650 and it's set for upper rpms as well?
 
length of the rod has very little or nothing to do with rpm's, spring tension overcoming the governor weights does, shortening the rod a little at a time should cure it
 
Dodgeit, You have received a lot of good feedback
and there are a lot of things to look for. But I did
not see anyone mention a worn out butterfly shaft.
If the throttle shaft lets in too much air where it
goes through the carburetor body, the air adjustment
screw will never adjust out like it should. You must
replace the shaft to stop that excess air intake.---
Derrol in Texas---
 

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