Bike Stalls - Hard Throttle Transition

[Tarheelbob]

A few times recently, my C-14 has stalled when making a quick transition from throttle-on to throttle-off coming to a stop. A good example is a going up my steep driveway with a solid throttle input for the incline, then snapping it shut for the short turn area at the top of the drive and the bike stalls. The bike is fuly warmed up when this happens and seems to be idling fine. Throttle free play is minimal. It has also happened when making a short stop at an intersection. This has occured about three time this past week.

Background: The bike is just back on the road this past week for the first time after being down for winter maintenance since mid-January. Valve adjust, coolant change, new tires, oil, etc. Other than this hiccup, the bike is running smooth as silk. Mine is a 2009 C-14 ABS with 23,700 miles on it. This cut-off had never happened before.

I will be double-checking idle speed and throttle play. Any insight from the masses?

[texrider]

Use a length of tubing to listen around the TB's for any sort of vacuum leak. Check the ignition coils are properly installed. Check poor wiring connections. Check if any spark plugs have been damaged/cracked.

[ZG]

What does she idle at? If low, maybe adjust the idle up a tad... 

[556ALPHA]

When I changed my bars out for longer sticks I paid extra attention to all details that I could have impacted.  I noticed that I could roll the throttle forward and SIGNIFICANTLY reduce idle.  On your next ride pay extra attention to this. 

[Tarheelbob]

Use a length of tubing to listen around the TB's for any sort of vacuum leak. Check the ignition coils are properly installed. Check poor wiring connections. Check if any spark plugs have been damaged/cracked.

Will double check connections and coils. Stick coils were checked, double-checked (paranoia) when putting her back together. Plugs were pulled (looked good), cleaned, re-gapped (again, paranoia. Hey, I'm an engineer, so what can you expect?  ) before putting back into head. I'll double-check these things right after I get the bike warmed up and confirm idel speed.

[Tarheelbob]

What does she idle at? If low, maybe adjust the idle up a tad... 

Yep. Check the basics first.

[Tarheelbob]

When I changed my bars out for longer sticks I paid extra attention to all details that I could have impacted.  I noticed that I could roll the throttle forward and SIGNIFICANTLY reduce idle.  On your next ride pay extra attention to this.

Great point. I had a little throttle drag (not "snapping" back) from my grip rubbing slightly against the grip heater wire and switch housing. By freeing that throttle play up, I may be over-closing the throttle, not used to reduced drag.

[texrider]

Great point. I had a little throttle drag (not "snapping" back) from my grip rubbing slightly against the grip heater wire and switch housing. By freeing that throttle play up, I may be over-closing the throttle, not used to reduced drag.

Yes. The return side of cable should only be able to bring TB's back to closed, and not exert more pressure. May need to loosen everything up and start from the actual trist grip stop, then bring the cable adjustments just to it.

[Tarheelbob]

OK, got everything squared away. Cold idle speed was 1100 rpm, warm idle speed around 900. Too low. Bumped the warm idle up to 1100-1150 rpm and things were much beter. Repeated attempts to "force" a throttle-close stall failed. Bike seems to be exactly as before.

Thanks for the suggestions, it did give me a chance to double-check things like throtle play, and examine the bike from stem-to-stern (found a missing body panel bolt, grrrr...). Tightened everything one last time. A good exercise.

MAN, have I missed riding this machine!

[VirginiaJim]

Adjusting throttle cables has always been a mystery to me.  I fiddle about and eventually get it but is there a special methodology to adjust them?

[Tarheelbob]

Well, I have followed the "back them both off, and start from scratch" method the last couple of times. But, I always end up with the same basic results: 3mm-ish of free play, or less. "Less" seems to be the way this bike likes it.