Todays crazy question

[jlaird]

When I shoot a bit of carb cleaner at the throttle shaft rods, I get a quick 200 to 300 RPM increase from about 1300 up. Engine also smooths out immideately. As you have seen from previous posts I can not get idle below this range nor can I get the mixtures set. Always says it is too lean. ie when you raise a piston 1/32 inch it wants to quit. The engine is also very rough at lower speeds will not accelerate properly or drop back to low speed when accelerator is released. All is well over 2K even on the road. Pulls good and smooth.

Now for the questions.

How much air leakage through the throttle bushing is acceptable??

How snug should they be? If you can tell they are moveing with your had is that too much?

Is there a way to measure this movement?

Do you think I am on the right track?

 

[GB1]

Jack:

It sounds like you are on the right track. 200-300 rpms seems like alot to me. I do not know of a way of measuring the play.

Patrick

 

[jlaird]

Should I be able to notice a movement in the shafts if I wiggle them by hand?? Is that too much??

 

[Trevor Jessie]

Are you wiggling them by holding the throttle plates. You should feel no lateral movement.

 

[jlaird]

No, not lateral movement, wiggleing them in the bearing holes.

 

[jlaird]

I have an extra set of throttle bodies that also need rebushing, thinking of haveing them done. Other than bushing all they need is a blast.

 

[jlaird]

This seems to be the test answer:

Put some heavy grease on the out side of the bushings, slap it on to restrict the air flow and see if that solves the problem.

Could not think how to test. Now I know.

Will try in the morning.

 

[bugimike]

I have done that before, and it should work for test purposes! Are the butterflys truly closing all the way? Does it still run after the throttle screws are closed ALL the way? It does sound like you are drawing too much air from somewhere!! Besides grease, to check for leaks, spray carb-cleaner where you would put the grease, if there is a noticable difference in the way she is running, you are sucking air!!

 

[jlaird]

Oh yea noticeable difference with carb cleaner at the throttle shaft inputs, two to three hundred RPM. I just want to double check with the grease and make sure all else is ok. Will report back on findings tomorrow. Can't wait.