carbs overfowing

bob64bob · Post by **bob64bob** » Wed Sep 05, 2012 9:21 pm

i have a problem with a carb overflowing when the bike is on the side stand, stand the bike upright and it stops so i dont think its the needle valve , it was fine before i cleaned some crap out of the bowls checked float ht which were fine and cleaned a lot of rust and silt out of the tank.

any one cast any light on what could be at fault
cheers

headcoats · Post by **headcoats** » Wed Sep 05, 2012 10:28 pm

I would fit inline filters after you have sorted the problem

dave32 · Post by **dave32** » Wed Sep 05, 2012 11:25 pm

it can only be 1 of 2 things,
Needle valve is worn (the viton tip) and not seating fully or..
Float height is too high.
As it stops when its upright it points more towards float height,worth double then treble checking as its quite awkward to get it at just the required angle without compresing the needle valve pin.
Not stateing the obvious but i will say it just in case (easily done

),a higher reading will give a lower fuel level and vice versa.
Also make sure your measuring as the manual states (will either be to the gasket face or without a gasket ).
If your getting alot of crap out the tank then as said above,fit some in line filters until youve sorted the tank (flowliner?internal coating maybe?),worth taking the tap off and checking the filters there as dirt shouldnt get by them.
HTH

KR-1R · Post by **KR-1R** » Wed Sep 05, 2012 11:35 pm

.
.
it could be your float height, or perhaps the float pin has come slightly adrift when you reassembled causing binding on the pivot... or some more dirt lodged in valve (you would be surprised what might get down a fuel line when it's unplugged from the tap) - as Dave said only the finest dirt will get past the fuel tank TAP filters/socks)

was there any buildup on the rubber tip of the float valve? careful not to damage the brass valve seat edge - nothing harder than a q-tip - no screwdrivers [-o<

?sometimes inline filters can slow down flow long enough to be problem when wide open?

http://www.youtube.com/embed/KcNfci9OruU

^^^ or maybe this guy hadnt clamped the hose at the tank (drawing air)

bob64bob · Post by **bob64bob** » Thu Sep 06, 2012 12:02 am

cheers all for info
will double check float heights again

Mark66 · Post by **Mark66** » Fri Oct 05, 2012 11:16 pm

Had a similar problem myself. Turned out the floats were sticking on the overflow tube. This was due to the fact that the floats weren't straight. There's not a lot of room in the float bowl, so if the floats aren't straight, there's the possibility they will catch on the overflow tube, more so if the bike is sitting at an angle. well worth a check.

fred · Post by **fred** » Sun Oct 07, 2012 9:18 pm

i bent my brass overflow tubes 3mm to the centre so they touch the main jet casting ,away from the float,for no other reason that they interfierd with the floats when taking em of

Mark66 · Post by **Mark66** » Sun Oct 07, 2012 10:13 pm

I tried that and the brass tube snapped where it went into the bowl

Should have probably warmed it up a bit first. luckily enough had a bit of brass tube to repair it.