carb leaking petrol!!!

[sarrebmat]

i have just removed and cleaned my carbs, and installed some new coils. at this point i have left my airbox off and got the beast running (now firing on all four cylinders). However as the bike was gently turning over i saw petrol comming out of a small round hole in carb no4 (last one on right) is this serious or can i fix this prob?????? i would be glad of some assistance

Yours Gary. Chadderton,Oldham, Manchester

[John]

That may be the vent for the float bowl, and if that is the case, then the float valve (needle & seat) are stuck open, allowing the fuel to flood the carb, and run out into the cylinder, and airbox.

[ratbyk]

Flooding

Gary, as John pointed out, this carb is flooding. It could be "dirt" that has gotten on the N/S and not allowing them to "seat" properly. Some times you can get lucky. Try tapping on the float bowl with the plastic handle of a screw driver a few times. Don't get carried away and use blunt force and break something but a few good wraps will sometimes dislodge your problem dirt/hair/whatever. If it does the flooding will stop and you are good to go. Just keep an eye on that carb for awhile. If it continues to flood, sorry, carbs are coming off again. Replace the needle and seat and recheck the float level.
Ken/Sooke

[petevan]

I had a similar problem right after I cleaned my carbs. I was very frustrated when I couldn't find the problem. It turned out that it was a little piece of dirt (or debris) that was not allowing my floats to go all the way up. In result the floats couldn't rise to shut of the "valve" to stop letting gas in. It took a couple of times of cleaning to get it right. I would be a little leery of knocking the whatever is causing the problem loose because that just means that what ever was causing the problem in the first place is still in the carbs and if not there it will run through the cylinders. I found the best thing to do was to take the carbs completely off and submerse the in a carb dip. The spray works well but doesn't always get the all off the gunk out. Hope this helps

[skids]

Turn off the petcock ("RUN" for a standard), drain the bowl and leave the bowl tap open, open the petcock to prime and catch the fuel below the bowl, flush out the particle, close the petcock (if standard, "RUN" ), close the bowl tap. If it is rust from the tank, you had better get some inline filters. Pieces of the rubber from the petcock holey gasket or gunk from old fuel line can stick open the float as well. Also, I have seen bad spring action in float needles sticking, bad pivot action on the float axle. Watch out for oil contamination in the crankcase!

[sarrebmat]

thanks for all the advice, got to get this dammned machine working before wednesday. Will try all your ideas. ill tell you if i get if sorted.

[uk1.1s]

Carbs leaking

Brute force and ignorance has helped me through some tough times with the XS11

The odd carb that starts to overflow can sometimes be solved by a shock to the carb body which I guess either dislodges a piece of dirt in the system or just unsticks the carb float which isn't moving very well on it's pin.

Inputting the appropriate shock to carb takes many forms depending on where I am with the bike.

Option 1: Whilst out somewhere I have managed to stop the carbs mis-behaving with a well aimed kick to the end carb whilst the bike is on the side stand.... For this a Special Tool is needed "Ex-German Army Para boots UK size 9".... sizes may vary... those of you with Size 12's...watch your aim!

Option 2: At home you can zoom in on the appropriate carb a bit better with the 2 hammer approach. Put the end of the shaft of Hammer 1 (usually the smaller of the 2) against the side of the troublesome carb..... Hit the top of the shaft (starting gently until you get really annoyed) where it comes through the hammer head using Hammer 2. Make sure that the shaft of Hammer 1 is tight against the carb as you don't want to break anything!! If all else fails see special tool described in Option 1 above.

If this doesn't work I usually have a cup of tea or a beer and resign myself that I'll have to get technical and take the carb bank off and see what's wrong.

If you do end up taking off float bowls to have a fiddle make sure the float on that carb is in the right way up (or is it just me who's done that) and that it moves freely, then take it off and check out the tip of the float needle and seat for crud. Also have a look at the float itself to see if it's filling with fuel (if there's a small hole or crack). If this is happening dunk it under the surface of a bowl of water or margarine tub with some petrol in it to find the hole. If it's easy to get at and small then seal with something petrol resistant (errmmm Araldite maybe?). If there is an almighty great crack in it then you may need to replace. Try NRP near Victoria Station in Manchester city centre - they do all sorts of carb bits

Best of luck Gary..... Oldham eh? I used to be a bit further north

[John]

Here's a problem thet I hadn't heard discused here before... On my spare set of carbs, I had found that the rubber tip on two of the float needles became detached from the body of the needle, and it was restricting the flow, and then it wouldn't shut off the flow when the engine was shut off.