Motorcycle Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter · #1 ·
I have a 1981 Honda cb650. I have cleaned the carbs, checked float heights, and installed new needles. I can't get the bike to idle. If I choke it, it will stay around 3000rpm then shoot up to 5500 rpm. And when I push the choke in, it dies. I checked the temp of the pipes and the two on the left are around 130 degrees and the right two are around 240 degrees. I checked the spark and had good spark on all 4. Compression is good and equal on all 4. I also dont have any vacuum leaks.

I returned the fuel mixture screws to factory settings, and bench sync the carbs.

I guess I'm just not sure how to adjust the fuel mixture screws if I cant get it to idle and hear the difference. If the left two are set too lean, could that be why its running cold?

Any help would be appreciated. Thanks.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #3 ·
They are on the bike now, I don't believe there was. All the butterflys were flush along the bottom. I don't know if there are other ways of bench syncing them, but I used two drill bits on the same size and made them all equal to the main carb.
 
1 - 3 of 3 Posts
Top