Idling really high after tuning

I started with the Idler mixture screws out 2.5 full turns, synced the carbs with my 4-bottle manometer. I barely had to tweak the butterfly valve on all three, but things looked pretty stable.

At this point, the idle speed was barely above 1000rpm and wasn't dying anymore (like it was the day before).

I put the colortune plug in 4 then 3 then 2 then 1 and all were passing with bunsen burner blue, I had to bring the idler mixture screw down a half turn on 1.

I took it for a ride for about 30 minutes and it ran smoother than ever before! Today it was all fine until I got about 5 miles from home, it was revving up to 5-6000rpm when I would take the clutch out. I parked somewhere and turned the idler adjustment knob to try to bring down the idle speed with NO luck. One thing I noticed is that the "choke" seemed to be slightly stuck open even though there is no tension on the line. Could this be the problem?

 

Yes. Take a look at how the cable is routed. Make certain it is not getting hung on anything and the enrichment plungers are closing completely.

Gary H.

 

That is the problem, the plungers get hung up on something, but the cable is slack and fully released. What would cause that? Should WD40 be brought to the party?

 

Nooooooooooo! WD-40 displaces water. To lube the cable go to auto parts store and buy a can of cable lube. You need to visually inspect the plungers while operating the enrichment circuit to see if you can determine what's causing it. If you don't find anything you may have to pull the plungers.

Gary H.

 

I know enough not to use WD-40 on the cable! The plungers are the problem. I may need to buff them down or something with some fine sandpaper (or something else?), would that work?

 

My apologies but some members think wd-40 is a all purpose lube (no pun intended). Use a scotch brite pad. Also inspect condition of the dust caps. If dirt or grim is getting past the caps you'll need to replace them.

Gary H.

 

The caps were all replaced a few weeks ago with the carb rebuild. I'll clean the plungers with a pad, thanks for the advice!