Topic: Starting on 3

[philcarroll_1985]

Getting my cb400f back in the road after 4 years, carbs have been stripped and cleaned, fresh fuel etc. When starting from cold the left hand side exhaust header is cold compared to the others for a little while then heats up, is this normal? Also, the bike will idle but the revs will increase significantly on their own to around about 4k. Any thoughts? I've read maybe carbs require balancing?

Sent from my VOG-L09 using Tapatalk

[69cb750]

Getting my cb400f back in the road after 4 years, carbs have been stripped and cleaned, fresh fuel etc. When starting from cold the left hand side exhaust header is cold compared to the others for a little while then heats up, is this normal? Also, the bike will idle but the revs will increase significantly on their own to around about 4k. Any thoughts? I've read maybe carbs require balancing?

#1 cylinder starts to run with delay, #1 missing fuel, compression, ignition.
Check compression  on all cylinders.
Check spark plugs, carbon or oil build up can also cause this.

[BenelliSEI]

After checking what’s already been suggested, dfinately a good carb synchronization, with 4X good gauges. Nothing beats it! Your bike will idle and run far better. A mechanical bench sync., before installing the carbs is a good start, but vacuum sync is far superior.

Lastly, if you installed 4 new NGK plugs, replace the one in the cool cylinder. On more than one occasion, a lousy, faulty, new plug has fooled me for a few days. Or try swapping it over to the other end. If the problem moves over there, you’ve solved it!

[philcarroll_1985]

Thanks both for your input, oddly today this issue seems to have gone away on its own I'll keep an eye on it. Ive already bench set the carbs but a proper synch is still to be done

Sent from my VOG-L09 using Tapatalk

[newday777]

Thanks both for your input, oddly today this issue seems to have gone away on its own I'll keep an eye on it. Ive already bench set the carbs but a proper synch is still to be done

Sent from my VOG-L09 using Tapatalk

Was there a change in ambient air moisture? If drier air made it start on all 4 you have a leaking spark plug wire and/or plug cap.