long term carb problem... I'm losing the will..

[leef82]

so I've been rebuilding the bike over the last 6 years and after spending crazy amounts of money on it, it hasn't actually made it back on the road... there has been other issues that have held back it most of the time even though it was 95% complete which included a leaky rear shock which is now sorted......

anyway even though I have had the bike running the carbs have always been an issue... at first after rebuilding the engine the front right carb leaked until I tapped the float chamber a number of times... then when the bike was left for 6 months or so it would not start at all.. some of this was down to starvation and other times flooding... which has resulted in two lots of spark plug replacements...

Last summer I thought I had sorted this and the bike would start up and run fine then on the day of the mot it flooded due to me turning the engine off not long after starting it ( had to take an important phone call, wish I hadn't now). after this it wouldn't start again, I checked everything possible electricall,y incase I was having weak spark problems... I even changed the spark plugs again with new ht leads from rick o. I also recently decided to replace the float needles which I was 100% sure was the problem as they was on later inspection sticking bad.. the replacement rick o ones were operating and springing back how they should.

so today I managed to get it started with the choke on and it was running a little quiet but once again fuel seems to be leaking from that front right cylinder even after taping it a few times its still leaking on second start up... and now I fear I've flooded it again as it won't start..
any thoughts lee?

[leef82]

ok so got it started again and is running with the choke off beautifully, nice and crisp through the revs... the fuel leak seems to of died down a bit.... but when you shine a torch on the carb you can see it seeping down above the float chamber join but can't actually see exactly where its coming from..

[richyrd5]

Sounds like a carb strip is in order,spesh if they've been sitting for a while..these bikes are very carb/plug sensitive so id start there..

[leef82]

I've stripped and cleaned the carbs loads of times now, last time was in February when I fitted the new float valves and they have been sat dry since then. I took the carbs back off yesterday and noticed what looks like a crack in that particular float, I submerged the float in hot water and there appears to be very tiny bubbles sitting on it, when the bubbles are wiped away they slowly reappear. Even though I can't hear any fluid inside the float I suspect that it may be possibly causing a problem.

lee

[st22041967]

let me know if your floats knackered. I'll send you one from my "for spares" carbs for the price of postage.PM me if you NEED it.

[leef82]

thanks st22041967 , I think I've got one sourced but if no luck ill PM you.... cheers.

[Morespeedvicar]

Also clean the holes were the float needle valve goes into, sometimes they get sticky with old fuel.

[pptom]

Had something similar but not the same on another bike. Turned out the fuel line was internally breaking down. I could clean the carbs perfectly, but not long after one would stick again due to debris being washed down with the fuel.

[leef82]

@ Morespeedvicar , yeah I did that when I replaced the float valves so should be ok, as its only had fresh fuel go through since fitting them...

@ pptom , do you mean the main fuel line from the tank or the ones that separate off to each carb? as the main inlet from the tank and vacuum hose were also replaced within the last year with rick o parts.

[amorti]

http://www.litetek.co/Carb_Kit_Honda_NC30.html