Carburetor Check Ball Problem

[usedtoolman 19]

There are two different check balls used in the O&R carburetor. The 1/16" ball appears to be the older version and the 3/32" a newer version. My experience with the 1/16" balls has been terrible. They tend to stick shut even after the carburetor is thoroughly cleaned and even if the ball is replaced with a new one.

 

Has anybody else had this problem? Does anybody have magical cure for this problem?

[Wallfish 698]

I've had plenty of issues with those small ones too.

What do you think about removing a very tiny bit of material from the seat the ball sits in?

[usedtoolman 19]

The problem with trying to alter the valve seat is that if you don't get it perfectly smooth and round it will let gas leak past it. I don't know of any easy way to alter the check ball seat.

[Wallfish 698]

I wonder if something like a diamond burr would work? Just to kind of polish it. Maybe they make a finer grit?

Something like this

http://www.ebay.com/itm/600-grit-30-DIAMOND-BURR-BITS-1-8-FOR-DREMEL-rotary-tools-glass-metal-Ceramics-/161255991787

[Laserscottman 4]

Possibly to solder a ball onto a brass tube and use it as a lapping tool, with some fine compound?  or do the same with a fuel needle from a Walbro or Zama carb that has an all metal needle, to get a flat taper rather than a ball shape, so the surface can seal better.

Edited March 31, 2015 by Laserscottman

[gary 0]

Wallfish:  What are the screw settings for the carb on a Ohlsson and Rice tiny tiger, it has two screws on the throttle; I set the needle at 1 1/4 turns.  Gary

[Wallfish 698]

 

Original post by usedtoolman.

 
"If I recall there is one more factor on the needle setting. If you have a slotted needle
the setting is 1/2 turn as opposed to 1-1/4 for the non grooved needle."

 

Also see the last post in the carb tutorial thread.

The other screw limits the butterfly and will need to be adjusted with the engine running