Runs not as well when fully warmed up

[aerologic]

Hello all,

My RE-5 runs pretty good until it is fully warmed up which takes a while. The temp gauge gets to it’s vertical point at a reasonable rate so I think the thermostat is fine plus it works as expected at the expected temperature when in water on the stove.

But when it is fully warmed up, which may take 30+ miles then I see issues. I usually don’t ride it too far so I’ve put this off for a lot of years but now I’m retired and I can tackle it.

Here is what I see. Again it runs fine and by fine I mean no dead spot really and I can give it full throttle and it accelerates nicely.

When fully warm, if I’m at 40 -60 MPH and I give it full,throttle suddenly it bucks some and is not pleasant.

The carb was ultrasonically cleaned by somebody else (Sam) and I do believe I have the butterfly set correctly ( I have the tool).

I’m curious if what I’m seeing is a symptom of rich or lean or what I should look at..

I’ll get the carb cleaned professionally again if need be.

I have the standard jet in there. A few years ago I bought several and I did mess with them some with a little success.

I’ve not checked compression in a while but it was good. It does idle nice.

I’ll take suggestions. I have more time to work on it now.

Thanks!

Dave P, near Cincinnati 

[goandy]

Check the enrichment pump diaphragm underneath the carby... other than that it's set and reset all the cables, play with different jets and stand on one leg whilst you're doing it. Not sure if the standing on one leg bit actually helps but with these carby's anything is worth a try!
Edit: before you tear it apart, take the intake elbow off the carby, give it throttle (whilst engine off) and look for a fine squirt of fuel into the carby throat. That will tell you if the diaphragm and circuit is working ok.