Carbs leaking like a fountain

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timsha

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Nov 17, 2014
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Hi,

During the winter i put new throttle cables on and took the opportunity to replace the throttle springs in and reinstated the choke (which was previously missing from the bike). Otherwise didn't do anything else to them - I didn't have the float boals off at all. As i couldn't remember which position the needle clip was in before (as the bike was running fine) i put them on the middle positions.

Now, as soon as i turn my petrol taps on, my carbs leak a lot of fuel (like a fountain).

So i removed the bowls to check for a sticking float needle....the PO had been a bit overly generous with that sticky blue gasket stuff and some of this had got on the float spindle ends where they seat. cleaned everything up and although i didnt have new gaskets (sunday) I put the boals back on. Tried opening petrol taps again - still freely flowing petrol after a few seconds....coming mainly through the bleed button.

I have also tried changing the clip position (although not sure if that has any bearing on the carbs flooding)....have tried in the second and third groove from the top of the needle) which didn't help.

Any ideas anybody?
 
check in again and again in case float shaft hanging on gasket over lap and also the ticker device not shifted too low so holds floats down more now the bowl seated closer to the body w/o the extra goop in the way. Not likely but maybe float needle ends buggered on their seats. Such simple machines what could go wrong.
 
Thanks Hobot!

The floats are definitely not too high when the float needle engages. They're about 3 mm from the rim of the bowl.

The ends of the float shaft or spindles are however covered by the gasket which when put under a bit of pressure does restrict the free movement of the float (it moves a lot slower). I have now cut the bits off which cover the spindle ends and it moves much more freely so will try fitting again.
 
ugh Tim I'm get as frustrated fumbled fussed as you so was hoping you tell me what's actually the problem. 3 mm low float seems a bit low - but I gave up measuring and just knock needle seats till runs w/o leaking then diddle floats enough pilot screw can completely compensate for easy starts and nice idle - though ideal to shoot for is 1.5 pilot turns out - yet my prefect slow idle Trixie pilots are both under 1 turn out and so good no incentive to bother carbs again. Dang ticklers are tin toy construction so may be able to fumble them a bit higher in case they are keeping floats depressed like your mood. Drives me bonkers when I try to fix/improve one thing and do - yet caused or uncovered something worse again over my head.
 
Well, it seems, that the gasket (which was a bit sticky) was actually impeding the float spindle i cut out those lobes on the gasket away and it seems to have cured the fountain like leaks....A leak from the banjo wasn't helped by the extra fiber gasket that the PO had above the fuel filter inserts....as far as i know those also serve as the gasket (no fiber washer above them on my other commando) so removed them and this leak is now better but by no means perfect. The plastic has probably hardened an not sealing perfectly. Tomorrow will get new bowl gaskets as they are still weeping and fuel filters....bikes is idling at 3000 cos i put adjusters in carb caps (were missing) and haven't compensated for that yet.

When starting it is sounded weird then with one pull on the throttle one of my 3 yr old sons toy cars shot out of the left exhaust pipe!!!

Tomorow is another day!
 
Tim,
Plastic banjos are not the best as well as plastic float needle valves. Hopefully you have the Viton tipped? I would get the Alloy banjos with the 180-degree spigots as per 850 types with all lines behind and under the carbs. Examine the contact surfaces where the fiber washers live and make sure the banjo bolts don't get cross-threaded. I have seen buggered threads here and the only solution is to source another float bowl.
Hope it works out for you.
Cheers,
Thomas
CNN
 
The float spindle does not need to be free....Trimming gasket over the spindle could cause float level to change, allowing spindle and float to raise....The float should move freely on the spindle and if not, shine the spindle a bit..
 
How are the float needles ? Has a bit of the blue goo has made it's way in between the needle and seat.

Greg
 
If you trimmed the gasket to free the spindle ends, that is your problem. I did a write-up on this some time ago which LAB mentioned.
Jaydee
 
I had a carb open for a photo.
This is how the gasket should look.
Carbs leaking like a fountain
 
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