Bummer! Too slow to idle down!!

[igya]

I can't find a thread talking about my problem, so I'll try my own. My '80 Mikuni 34 carbs are slow to idle down when I come to a stop. It takes about 5 seconds to reach idle speed. When I unscrew the throttle stop to a decent idle, it will quit in about another 5 seconds. When I set the idle to where it will stay running, it goes back to the "slow to idle down" mode. I've been through both carbs with a fine tooth comb, and everything seems to be good (but obviously not). This has me worn out man! Help would be appreciated.

p.s. The engine was running perfectly until I put its carbs on another 650 and started using this set from a different bike that's scrapped out. I could put the original carbs back on but then I'd still be short a set.

Read more: http://xs650forum.proboards.com/index.cgi?action=display&board=Fuelsystem&thread=2790#ixzz1VDsPOYJh

 

[Travis]

Sounds like your hanging is due to a lean condition maybe from a vacuum leak. Did you try the trick of spraying carb cleaner all over the carb holders with the bike running to see if it revs up from cracks or leaks around the carb holders?

Could be all sorts of things I guess.. Too much fuel or too much air, carbs not synced, dirty carbs, wrong jetting, worn parts, damaged parts (like mixture screws), bad diagrams..

What are your mixture screws set at? Are those little o-rings and washers in there still? Do you still have the stock air boxes? Did you check the jetting in the replacement carbs when you cleaned them?

By the way, your "read more" link doesn't contain any more information than you posted here. Looks like a copy and paste. Did you actually search here for your problem or did you just search the proboards site?

 

[igya]

Sounds like your hanging is due to a lean condition maybe from a vacuum leak. Did you try the trick of spraying carb cleaner all over the carb holders with the bike running to see if it revs up from cracks or leaks around the carb holders?

Could be all sorts of things I guess.. Too much fuel or too much air, carbs not synced, dirty carbs, wrong jetting, worn parts, damaged parts (like mixture screws), bad diagrams..

What are your mixture screws set at? Are those little o-rings and washers in there still? Do you still have the stock air boxes? Did you check the jetting in the replacement carbs when you cleaned them?

By the way, your "read more" link doesn't contain any more information than you posted here. Looks like a copy and paste. Did you actually search here for your problem or did you just search the proboards site?

Actually, I didn't create the "Read More" link. The forum program must have included it because I did do a copy on a different 650 forum. I really think the carbs are the problem because everything else was working just fine before these carbs came on the scene. I'll check the things you suggested once again. Thanks

 

[Travis]

Well this forum software will convert anything that looks like a link into a link, but it had to be included in your copy and paste to begin with.

Anyway.. What year bike are these carbs on? I guess I assumed '80 but now I realize that's what year the carbs are from.

 

[igya]

The engine is a '77. I'm using another set of the 34mm carbs on a '72 and they work just fine. I think I will swap carbs around and make sure it's actually a carb problem.