Generac/ Dixie Chopper carburetor bleed air jet O-rings.

[Auto Doc's]

Hello folks,

I have a 2005 Generac 15KW 992CC model OE 6221 engine with a bit of a hunting surge at high RPM. The same engine was used on the larger Dixie Chopper mowers.

It has an OE carburetor that has been cleaned well, and the bleed air (pilot) jets were resized just a little to resolve the rapid low idle surging, but I still have a very slow throttle "hunting" of the RPM when running at top speed. (3600 RPM/ 61 Hertz) This engine is servo throttle controlled and there are no intake or carburetor mounting gasket leaks. Applying a load when powering my house makes no difference.

Applying the choke slightly does not help the condition, so it is not a main jet "over lean" issue.

The tiny O-rings on the bleed air (pilot) jets did appear slightly deformed and felt rigid when I was putting it back together, so I think that is where my problem is.

I already know these O-rings have to be a specific size, and others look similar from the aftermarket carburetors, but they are slightly fatter and do not let the bleed air jets slip into place like they should.

Also, I am not a fan of the aftermarket carburetors for this application (Been there already and it was worse)

An OE carburetor is exceedingly high $$$ and I question if they are still genuine or just re-boxed clones.

Any help is appreciated (A rebuild kit would be nice if they can be found)

 

[Tiger Small Engine]

Hello folks,

I have a 2005 Generac 15KW 992CC model OE 6221 engine with a bit of a hunting surge at high RPM. The same engine was used on the larger Dixie Chopper mowers.
It has an OE carburetor that has been cleaned well, and the bleed air jets were resized just a little to resolve the rapid low idle surging, but I still have a very slow throttle "hunting" of the RPM when running at top speed. (3600 RPM/ 61 Hertz) This engine is servo throttle controlled and there are no intake or carburetor mounting gasket leaks. Applying a load when powering my house makes no difference.

Applying the choke slightly does not help the condition, so it is not a main jet "over lean" issue.

The tiny O-rings on the bleed air jets did appear slightly deformed and felt rigid when I was putting it back together, so I think that is where my problem is.

I already know these O-rings have to be a specific size, and others look similar from the aftermarket carburetors, but they are slightly fatter and do not let the bleed air jets slip into place like they should.

Also, I am not a fan of the aftermarket carburetors for this application (Been there already and it was worse)

An OE carburetor is exceedingly high $$$ and I question if they are still genuine or just re-boxed clones.

Any help is appreciated (A rebuild kit would be nice if they can be found)

Try installing a spring onto the throttle connection to stop the slight surging at WOT.

 

[Auto Doc's]

Hello M.,

The servo motor to throttle arm link has pop on nylon ball sockets and there is absolutely no free play between them. I have checked. Thanks for the idea. The throttle shaft also has no excessive play when checked

This carburetor design is quite tedious to get on and off the machine, but I have learned to double nut the mounting studs and take them out and that allows enough room to lift the carburetor up and out without removing the intake.

The Generac built big V-twin engine are well built, but their designs are not very repair tech friendly.