runaway idle

rebuilt carbs last fall. it starts and has kind of a lumpy idle and then fast idles up to about 5000. Where should i start on diagnosing?

 

'choke' on or off?

you may have an air leak or the carbs may need cleaned again.

 

-Enrichment circuits

-Sync issue

-Float levels

-Vacuum leak

 

choke off. im thinkin vacum leak. Enrichment circuits should be good but.... i know when i rebuilt concours carbs and gold wing carbs i had them in and out about 3 times each... oh welll

 

I've been caught with a hanging throttle cable before, the little bit of slack at the carb end can easily disappear when setting the idle during tuning so keep an eye on it throughout the process.

Might also be a vacuum leak ... mixture leans out and the revs run up. Make sure the seal is tight between carb and boots on cylinder head side.

Another area to check is the vacuum port test point caps. These are on and off a few times during tuning and it's tempting to leave the little clamps off and just push the caps on. If they are old and hard they won't seal with the clamps off and leak enough air to lean out the idle.

 

all this makes sense. the boots were not in the best shape when i reinstalled them and the the caps i did not even think to check. I am assuming cha cal will have all of these items for a price?

 

All the above,
I went through hell over this only find out my little rubber vac boots wasnt sealing and once the engine got to temp it acted like that.
something to make sure about as you go through the rest of the possibles.

 

sorry just saw the last post. lack of sleep please disregard.

 

After you've checked throttle cable routing etc, make sure you check idle adjuster too.. (ie rule out the easy stuff first)

Once/if you establish its neither of these simple things, refer back to the posts about vacuum leaks, carb issues etc.