Fuel surge with Weber DMTL....float problems.

[Ian Carvell]

Does anyone know what I can do to stop the fuel surge in my Weber DTML.

I am using it on my racecar and it runs fine on the road with the 8mm float height as prescribed elsewere on here, but on track I get really bad fuel surge on long right handers. I have managed to fix it by raising the float height really high, infact so high that it floods really bad at idle....but that is the only thing I can do to get the thing to work on track.

I end up raising the float level when I get to the circuit, then dropping it to go home....not good!

Any ideas on how to fix it....I am at a loss really. I did think about removing one of the floats, but then it will probably surge on left handers instead of right handers.

I know these carbs are used on oval racing so this problem must have been fixed by someone!!!

[Mike the Founder]

interesting - never heard of this.
Are you sure its a corner thing and not that you have your foot flat under duress for long periods and there fore are using more fuel than is getting into the carb? this is not uncommon
try this:
it may be you are not getting a high enough fuel pressure to the floats, are you using elecrical or mechanical pump?. If a mech one do you have a fuel return line in place? or wven worse the old fuel splitter on thr front of the cyl head ( if you are unbolt it and throw it away!!)
if so - block it up, and put the fuel direct onto the carb. Float adjustment may be required.
If an electrical one - you will have a return in place - try restricting it some more.
thats all I can think of...