Briggs & Strat wont idle stable, rough/low idle

[MEDEL514]

And you cannot properly diagnose anything else until that is corrected.

That's what I'm trying to figure out, how do I correct that low/surging idle?

 

[ILENGINE]

Compare your spring tab location to this one I have attached. Wish the quality was better but you can see what I am looking at.

 

[MEDEL514]

Compare your spring tab location to this one I have attached.

Looks about the same as mine. Mine had no damage, and no signs of bending. I bent it on my own trying to play with the adjustment, but I out it back to where it was originally.

 

[Scrubcadet10]

I would take the carb off and give it a good cleaning.
make sure the holes in the bowl nut are clean etc.

 

[Scrubcadet10]

 

[AVB]

You would want to bent in the direction that puts more tension on the governor spring to increase rpms.

 

[MEDEL514]

I would take the carb off and give it a good cleaning. make sure the holes in the bowl nut are clean etc.

Carb cleaning was one of the first things I did when I put on all these new parts.

You would want to bent in the direction that puts more tension on the governor spring to increase rpms.

I did that by manually holding tension on the spring, and it did increase the RMPs, but the idle was still bouncing all over the place. I'm lost what to do.

 

[Scrubcadet10]

So it ran fine at higher RPMs, but at lower (idle) RPMs it surged?
As Ilengine said these engines are made to run 2800-3600 rpm.
no need for a pushmower to idle.

 

[AVB]

What is the model and type number of this engine so I can look-up its IPL to see if it was ever intended to idle. But as noted does it surge at the higher rpms?

If it was intended to idle and the surging is only at idle it require a jet resizing as most of these later carburetors are non adjustable.

Also with it being a 6.25 hp I assume it is a OHV engine so have you checked the valve clearances?

 

[MEDEL514]

I'm sorry to confuse, but you are correct, it doesnt have an idle. The normal operation RPM is not being reached because the RPMs are bouncing and keeping the motor running at a lower RPM than normal. When I tried to pull on the spring to get it into the normal RPM range, it still surged and would not smoothen out.

The only time I can get it to run smooth is when I hold steady the black plastic carb valve that the spring attaches to. That black plastic valve has an rod that connects to another arm in the back of the engine. I'm guessing that this is what's supposed to open/close the carb to a stable idle. What controls this arm, and how is it calibrated?