Ideas for running on all 4 cylinders I'm running on 2?

[jmp]

An interesting problem on a twink running on 40 DCOE Webbers,

Engine running a little rough when idling but goes very well once on the road. Decided to look at the problem and thought I would check firing first of all. Remove plug leads 1 and 2 noticeable drop in revs for both. Remove no 3 lead no difference. Remove no 4 lead no difference. Replace leads go for a run car goes well and revs well. Get back and same scenario. I can remove leads 3 and 4 and no drop in revs but there is a strong spark there.
So far I have changeds plugs/leads with no difference. There is a good spark with the engine running on tickover and plugs in the leads.
I'm beginning to wonder if it is fuel related as it is both cylinders fed by the same carb. In the history file it is noted that the carbs are worn.

Anyone had a similar problem?

John

[jmp]

Just read tvacc's similar problem.
I forgot to mention :
Firing order correct on mine.
Fuel level looks the same in both carbs.

[Chancer]

If it runs well on the road I would look at the carb balance, it sounds like at idle the rear carb has the throttle butterflies closed.

[jmp]

Thanks,

Hopefully I will find out tomorrow as I am off to see someone that has the equipment to check it out. I'm driving it there which is about 30 miles away from home which will be the longest journey I will have done in it yet.

Regards,

John

[Chancer]

A simple piece of tube will suffice to get your adjustment much closer than it currently is, I would not drive the vehicle any great distance on part throttle opening until I had got the balance at least somewhere close.