scavenge tube

[dmarshman]

has any one used 1/8" compression fittings to make a scavenge tube?

i really can't see it being a problem as long as the connection is good

figured I'd get some feedback from you folks.

[Don Moyer]

Compression fittings work fine. We used them for years before returning to flared fittings for no reason other than to be more faithful to the original configuration by Universal.

Don

[jarod]

I have a question with respect to the scavenge tube as well. I currently have a temporary 1/4 inch tube as I have broken the old one when I removed to service carb. I have the proper tube on order through Moyer. I noticed the engine has not idled as well lately and even tries to stall on occasion at idle. Also the motor used to start on first attempt and now it needs to be cranked a couple to times to fire up. Are these issues related to the larger scavenge tube.

[Don Moyer]

The 1/4" scavenge tube is no doubt the cause of your poor idling.

The original 1/8" copper scavenge tube allows only a small amount of suction to be applied to the bottom of the carburetor intake throat and a corresponding small loss of vacuum which is easy to adjust for with the idle mixture control. Your 1/4" scavenge tube represents a significant loss of vacuum which is not possible to compensate for with the idle adjustment valve.

Don