Topic: Who has CR29 carbs - stiff when the bike is running

[greenjeans]

Took the bike (‘70 CB750/836)  out the other day after almost 6 months.  A couple days before, I took the CR29 carbs off and cleaned them and moved the needle down 1 notch.  Really didn’t need much. 
Anyway, when the bike is not running the throttle/cables etc are very smooth both pulling and pushing.  Snaps back crisply.   But, when the bike is running, the throttle gets tight.  Will just about act like a cruise control and takes noticeably more effort to twist the throttle.
Cables are recent, lubed and silky smooth.  Throttle tube is also recent. 
Any ideas?   I don’t remember them like this.  Nothing is binding.  Throttle action is smooth from lock to lock.

Carbs are CR29s  only have about 3000 miles on them.   

Any ideas?

[robvangulik]

The only difference between running and not running should be the vacuüm pulling on the slides and the fuel flowing through the pipes and jets. I can''t see the fuel making a difference, but if the carb wall is bit rough where the slide is pulled against it, it could, maybe a bit of polishing could help?

[newday777]

Maybe you should edit the title to ....
Problem with CR29 Carbs- stiff when bike is running

That might get attention

[Tim2005]

Those CRs do get stiffer when the motor is running, I had to fit the push cable to mine to stop them hanging at times, though they would snap shut nicely with the engine off. I wonder if your return spring lost some of it's strength too?

[greenjeans]

Maybe you should edit the title to ....
Problem with CR29 Carbs- stiff when bike is running

That might get attention

Had to read that twice.