Float needle drilling

[Fordy]

Is it possible to take the needle valve apart to drill it as my 1.7mm aint cutting the mustard when driving flat out from 2nd to the top of 4th

Looking at it im not sure how on earth its mean't to come apart :confused: And like most things... if it goes together when made then it must come apart somehow :laugh:

[Kris M]

Some people have tried drilling them out but struggle to get them to seal properly when finished

[bigdur]

I bought my 2mm off ebay Germany. Might be this one? Someone will confirm I'm sure.
http://stores.ebay.co.uk/Vergaser-Teile-Weber-Solex-Dellorto/Solex-/_i.html?_fsub=9&_sid=93048234&_trksid=p4634.c0.m322

[Scoff]

They don't come apart, not neatly anyway :)

First up, dont go larger than 2mm else the head of fuel can be stronger than the float so the float is no longer able to shut the valve.

Best way is with a sharp drill clamped in a pair of mole grips or whatever. Holding the valve with the ball upward so that swarf can drop out you want to drill it carefully by hand. It should only take a few turns to neatly get through at 2mm.

Then do your best to blow out any swarf. Next you want to grab the ball bearing carefully with pliers and repeatedly push/turn the valve shut so as to bed the needle back in to the freshly drilled hole. If you don't do this, it will probably not seal because the jet will rest on the new burred edge you've just drilled. It's a bit like seating a valve in a cylinder head.

That should do you. Some times you can suffer with hesitation when doing fast gear changes with a big needle jet fitted. Thats the valve not shutting fast enough and the bowl level getting out of hand. Not always a lot you can do other than making the jet seal the best it can.

If you havn't already you should think about connecting the regulators reference pipe to the compressor housing. It will promote fuel pressure under load since the signal at the compressor should be a bit stronger than that of the plenum.

Hope that helps :)

[Fordy]

Cheers scoff that helps alot.

I'm planning on going 1.9mm first and see if that seals ok and is enough to keep the fueling steady