completly clean ALL the carbs passages.emulsion tubes.take out mixture screws.EVERYTHING.make sure all gaskets are not leaking.i know u said u have.but double check everything.coz its defo carb i would say.

mitchyboy01 wrote:Removed vac hose and sprayed in carb cleaner to the air jet and it started to fire. Why doesn't it fire normally.

If the problem cylinder fires up when you spray a flammable material in there, it would point to no fuel getting to the problem cylinder.

richyrd5 wrote:completly clean ALL the carbs passages.

I agree, but the only way to do this properly is via ultrasonic cleaning.

mitchyboy01 wrote:Do most garages do ultrasonic cleaning of parts?

Your best bet is to find a member on here that has a large ultrasonic cleaner that the carbs will fit in without being split (perhaps stick a wanted ad in the classifieds), it'll save you a fair bit of money. It won't matter if you need to clean one side of the carbs and then the other etc.

Many people own small cleaners, but to use those you'd need to split the carbs apart, it's not a particularly easy job to reassemble them.

Failing that, you may need to consider buying a used set of known working carbs.

daft question but there isn't a split in the carb diaphragm is there?

Just a thought, but I don't know if is possible without looking.

Can you fit the carbs back to front to prove them?
The fuel hose may need extending to fit a funnel or dummy tank, the choke and throttle can be hand operated.

arsey30 wrote:Just a thought, but I don't know if is possible without looking.

Can you fit the carbs back to front to prove them?
The fuel hose may need extending to fit a funnel or dummy tank, the choke and throttle can be hand operated.

Good shout! I can't work on it til saturday but will give it a whirl!!

Being the loon I am I scoffed my dinner and went out to my garage in the dark with a head torch on on lol. Was well impressed as I went from scratch to having the carbs off and switched around in about 20mins lol!!

Anyway, laid the petrol tank on the rear of the bike extended the fuel line to access carbs. Carbs were a tight squeeze when reversed and I scratched some off the black paint from frame but nowt a touch up won't cure. Got it running with the carbs reversed. It fired on all 4!! What!!?????

On covering the intakes individually by hand the rear two now make a huge difference to idle whereas the fronts are a little slower to react. The pipes were all smoking hot. Anyway I had to come in due to not wanting to die of carbon monoxide inhalation or piss off the neighbours any more.

I will go back out tomorrow after work and try to see if it will stay running on 4 or if it will cut out on the front 2 eventually.

A bit confused but at least I now know 100% it's a fuel issue and not compression or electrical.

Thanks Arsey!!

i would say u have an air leak somewhere.maybe carb rubbers are fubared.glad u now know what it is...or isnt!!

richyrd5 wrote:i would say u have an air leak somewhere.maybe carb rubbers are fubared.glad u now know what it is...or isnt!!

Hi Rich! Thanks, I feel like I'm gettin somewhere finally.

If it was carb intake rubbers the rears would still be misfiring even after I reversed the carbs.. When I just started it, it fired on all 4. Instead of just 2 before. The fronts which were the strongest before I suspect are now the weaker pots suggesting the problem has swapped cylinders with the carbs.

ah got ya.i thought as they were reversed the rubbers would bend a different way coz of different carb mouths.but t least u now know.i have a set ov carbs coming next week.i have been told they are all good.taken of a 20.000 km bike.if u want them pm me.otherwise overhaul yours.(or if its a uk bike vfrkieran has a set of uk carbs.)

richyrd5 wrote:ah got ya.i thought as they were reversed the rubbers would bend a different way coz of different carb mouths.but t least u now know.i have a set ov carbs coming next week.i have been told they are all good.taken of a 20.000 km bike.if u want them pm me.otherwise overhaul yours.(or if its a uk bike vfrkieran has a set of uk carbs.)

Thanks for the offer Rich. Going to have another go at mine and if no luck enquire into getting them cleaned ultrasonically. If I have any problems I'll be on to you for yours lol