Sticky Float Bowl

mar

mar

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Location
California USA
I have been noticing that one of my floats will occasionally stick dumping fuel on my starter motor. Of course several quick taps with my pocket knife will correct this.
What is the correct fix? The carbs were recently rebuilt (about 6000 km on them).When I remove the bowl what am I looking for?
Thanks, Myke
 
you are looking for a badly made float which is too wide for the pivot, and consequently "sticks" usually worse if the fuel level drops, as in, you have run the bike with the fuel taps closed, or maybe it has evaporated and also caused the float to drop lower than usual.You should not have to, but you will need to remove some plastic from the hinge part of the float to make it smaller and a looser fit.I will lay money that the float is coloured white, not the original (as new) black plastic
CLEM
 
In addition to Clems recommendation you should take a careful look at the float pin for crud or corrosion and also in the bore of the float.If it has fuel evaporate and been left sitting a very hard to remove gum can form.I also had a leaking float needle problem once and found what looked like a string of teflon tape holding the needle open occasionally,it was stuck at the inlet side of the seat body and most of the time the needle would seal.Drove me nuts for a while.So take a good look at the needle and seat too.
 
Well, I took a look at the float and it is the black ones. Everthing seemed to be operating properly.The hindge is not plastic. It is metal. It seemed to have lots of movement in it.
The bike will not be off the road for a while so I will let you know how things work out.
I am mocking up a Jota fairing and replacing the front caliburs, masters and painting .

I was not really planning on doing all this just now. It is just that one thing led to another and so on. I am just hoping I can get it back quickly.
 
well then I would say you need to replace the flaot valve and its seat,(stick a bigger one in it while you are at it, and do all 3 carbs) very easy to buy and perform, but not if you havent got some quarter drive sockets and the correct size, 8mm ? 9mm? cant recall.I have seen at least two carbs, butcherd by adjustable spanners/ mole grips/imperial sized tools  etc.A carefull check on the float heights will be in order as well, do you know how to do that?

CLEM
 
Clem, yes I have the correct tools.( I use the quarter inch drive socket to tap the bowl and be on my way)  :D
Just not the correct expertise. Can this be done with the carbs in place or do I need to remove them? I am wondering if it is possible that the carbs need work with just 6,000km on them.
 
Kinda depends on who done the work..

It is possible to change the fuel needle in situ but it's a bit of a fiddle, takes less real time in the end to pull the carbs off and do the job on the bench in good light where everything is easy to get at. Make sure you either remove the fibre washer under the valve body or leave it in place, don't end up with two fitted. Do all three valves at the same time and take care over setting the float heights (18-19mm)


  Keith.
 
The tiny fibre washers that live under the float valve is my guess.... Seal the base of valve and carb body.... WASTE OF TIME . ADD time to setting float heights !
 
mar said:
Keith, Thanks for the advice.What fiber washers are you referring to?
The carbs were rebuilt by Lance Weil.
Click to expand...
lance+weil+dunstall+domi.jpg


The Amals on Lance's Norton did not use them, maybe he forgot..Dellorto uses fiber washers between the float valve and the carb body
 
lets go a bit further,
to change the float vaves and seats as Keith say you realy must take the bank of carbs off the bike.If this is a 180, then dont "wiggle" them when you are removing them or you will break the female mounting sockets at the front of the carbs, pry them very gently and squarely away from the cylinder head,(some light oil or wd40 squirted at the plastic insulators will make removing very easy the next time if a 180), if a 120 then they are in rubber and fixed by jubillee clips, remember to remove the top cover from the centre carb, makes life a bit easier.

When you have them on the bench, unbolt them from the two metal carriers front and rear of carb, and you now have 3 seperate carbs,undo the centre nut on a float bowl and remove the bowl, then (with needle nose pliers) remove the spindle for the float and withdraw, the float valve should just about hang on the float so look at everything as you remove it, next you can unscrew the brass haxagon that is the float seat, when you have it out, there will either be a fibre washer (maroon) stuck to it, or (more likely) it will be in the bottom of the threaded hole that you just took the seat out of, that needs to be either left there or replaced, but as keith saye you dont want to end upo with two washers.

Dont forget to set the float height, do you know how to do that? and rebuild everything plus balance the carbs when on the bike ,do you have vacuum gauges?
CLEM
 
No I don't know how to set the float height. Perhaps this is all the carb needs is just setting the height correctly?
I have always thought you start with the cheapest and easiest fix first and work you way to the most ecpensive. :D
 
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