finally got my engine in the frame after being rebuilt carbs and airbox on all ready for the start and it fired first time. only problem is its only running on 2 cylinders? both are getting good sparks as they have new plugs and i have checked that but what else could it be? im sure there is a list but as i know nothing of the subject im stuck! any help would be greatly apprectiated
cheers

leave it as it is, everyone loves a V twin

cheers rich but i think id best get it runnin on all four

Only 2 new plugs? Move the working plugs to the non working cylinders and see if it follows them...

Plugs are always the culprit if all else is sorted...

no sorry all are new plugs but ill have a swap around anyway im gonna take the air box off tonight and have a look at the carbs to see if they are all seated properly, it ran ok before it was stripped and the carbs haven't been touched?

Try a spray of carb cleaner and see if it picks up - might not be fuelling at all?

As it stands though, they can take a bit to get going... my no9 does every morning..lol need to give the carbs a fettle but just not got the motivation or time right now..

cheers ill try that! Im going to have it set up at some point but i want it running before that happens, ive run out of favours with my mate who re-built the engine so im going to have to pay for it, after having my hours cut at work, even at mates rates thats going to be a push to afford it

Are all the connections behind the Speedometer in place and working fine? mine was onyl running on 2 cylinders a while ago, and it turned out to be the Speed Deristriction Resistor had fallen out and the ECU was in Limp Home Mode, kinda thing...

oo thats worth a check aswell before a strip down! is the resistor inside the speedo or is it easily visible?

are you getting a spark from all four plugs ?
check your coils conections if youv'e had your engine out check they are all back correctly (inc tight earth leads)