I think the body/mounting castings are too weak...
Although the head face and the carb flange may be flat the fact a halite sealing gasket is used allows a sufficient amount of 'flex' to distort the carb body when the nuts are fully tightened...
If two gaskets and a Tufnol thermal spacer are used the position becomes worse...
If a flat surface is bolted to another flat surface no distortion is really possible so it seems to me the gaskets are the only thing that introduces a variant...Ian
Yes I had the same thoughts Ian, the distortion that nips the slide happens at such extremely low nut torque values (Too low to even measure at a guess). It's heartening to here that it's not just me and that Horror has experienced the same problem and managed to get over it. However the process on a G3 might take me a month of Sundays unless I replicate the Tufnol block and gaskets on the bench/vice somehow.
I've sent my original carb back to Martyn who is more than willing to re-visit it and double check with the info from Amal.......I have just mailed them to see if it's possible to buy just a jet block which could just be the whole problem? (Or hole )
Incidentally, Martyn told me that the flange nuts should be done up to only 6 lbs torque. Ron
Ron, any chance of mailing me the carb spec card etc. ? The non /R carbs fitted to Nortons don't have the elongated slot / side drain and they do indeed piss fuel into the engine or back out of the inlet if there is any over-fuelling.
It's strange though, I've recently put new Amals on my Commando with no problem at all when tightening them up, but the B25 couldn't be done up at all without nipping up the slide. A spring washer under the nut or a blob of Wellseal on the thread helps to stop it working loose without it being tight. Loctite could end up undoing studs when getting it off.