Hitchcocks Forum

Hello to all.
I`m a new Enfield owner, just bought a low mileage 500 Classic 4-speed electric start. I`ve always wanted one and I`m loving it and using it every day.
It was stored for about 4 years before I got it so it has not been without a few problems. Most frustrating has been the clutch operation(either slipping or dragging)but thanks to the wonders of the internet I now know about the gearbox cover flex so have just got the stiffener kit to fit this weekend.

The other problem and reason for this message is the spitting back from the carb. It`s got an Amal 930 and S&B filter kit on it and a 1950`s style exhaust. I think I`ve got the carb about right, it was running rich so I raised the needle clip to the middle notch(it was on the bottom)and the plug looks good.
The problem is it keeps spitting back through the carb, sometimes spits and dies.
I `ve just discovered that there is movement where the exhaust goes into the head. Could this be the cause of the spit back? Is this normal? It looks like this is a push fit into the head so will a new exhaust gasket cure it?
Any advice gratefully received.

Hi Ivor, The push-fit exhaust can be helped by using bathroom sealant silicone as a seal. People always think it'll burn, I did, but after many years of use... it definitely doesn't. Also, are the exhaust brackets all holding it in place properly as they should... as you say it's moving a bit? Might be worth checking if it all lines up nicely. Good luck, glad you're enjoying it. Chris

Spitting back through the carb is often caused by an over lean mixture, in this case because you have a very free flowing airfilter and exhaust. It probably would n't be enough to just move the needle, the carb has to be jetted for the engine mods too. You may find it to be absolutely fine with the standard airfilter and exhaust but the mods are letting just too much fresh air into the motor! No doubt Mr H. will have jetting suggestions for that carb. (jets only cost pennies) on this site somewhere or they will certainly be able to offer advice over the phone.

Thanks for the replies. I am a bit surprised that there is no gasket for the exhaust into the head. Reminds me of the Triumph days many moons ago when they had the same set up. It was nothing but trouble but you could easily convert them to push over type with an adapter. I wonder if such a thing is available for Enfields?

As for the carb settings, your probably right about that. The person I bought it from did these mods then didn`t ride it so it`s never been set up properly.
Will phone shop for advice and in the meantime play with the pilot air and throttle stop screw again.

Does anyone know what the standard setting for the pilot air screw is,3 full turns out from fully in? That would be a good starting point.

Thanks for the help, doing the gearbox cover mod tomorrow.

Its actually quite clever engineering. The port has a slight taper, the factory pipe is designed to fit it snugly when bolted in position, a smear of silicone just fills the annular gap. Anyone who has had a bike which has the exhaust pipe attached by studs or a threaded nut will only be too aware of the problems when they sieze with heat. Many sealing problems on the Enfield occour when poorly fitting after-market exhausts are used.