Topic: Honda CB 750F2 Running problems

[Emraa]

I am currently rebuilding my old CB750 after being off the road for over 10 years.
I am having a baffling problem with the running.
It isn't running on no.2 (base carb) but running fine on others three. I have tried everything I can think of and would like to pick your brains - please help! It's getting very frustrating now!

 

[Bob Wessner]

Ten years standing is a long time. When you say you've tried everything, did that include stripping and cleaning all the carbs?

[Emraa]

yeah, stripping and cleaning the carbs was one of the first things i did. it just won't take in the petrol. It's really baffling me!!

[mcpuffett]

hi , have you got a good spark? fuel going to that carb ,then to that cylinder , have you tried easy start down that cylinder just to see if it will fire on it?   mick.

[CB750F2]

Check spark, compression and that fuel is getting to No.2 carb by opening the drain on No.2 carb. If all is OK try opening the throttle and see if runs OK at higher revs. If it does recheck No.2 carb idle circuit and float level. Pat, from Nth Qld

[Lumbee]

...also check #2 plug and see if there gas/gas smell on it...

[Emraa]

Have tried all of the above! Any more ideas???

[Dennis]

If you have fuel, compression and a spark visually sometimes the spark may not be strong enough. This is sometimes caused by the connections between the coil and the plugs.
Have you checked the spark plug caps (original Honda should be about 10k) and plug wires? Brand new spark plugs?