It's that black rubber corrugated thing that sticks out the top of the carby and has a lever attatched to it.Hit the Wiki on the left and i reckon there should be a blow up of one in there,check it out before you start ripping it apart,kits are redily available and quite cheap.

Thanks Bert, where do I find the accelerater pump?

Sounds like your accelerator pump to me

ok, going to read through my workshop manual and try and tune the carb.

clyons8, yep will check the dizzie but I think its in correctly, also I dont think you put the dizzie cap on 180 off as I has a locater and a clip....will check again.

Tune the carb.

If your last variable is the carburetor, then fine tune the carburetor. The carb is responsible for delivering the food to the engine, if everything is on check then check or tune the carb.

EDIT: Perhaps a 180 on the dizzie?

If as you say ignition & cam timing are ok, lift the air cleaner & check you get a good squirt out of your accellerator pump when ole mate tramps the throttle.

Just got my a15 running after new rings, bearings etc, its a standard motor with no mods. But it runs really bad, its timed correcty and has good spark. It idels fine but as soon as a you touch the gas it cuts out....like I can only just get it to move and there is no way I could get it out of first gear.
I,ve look for a manifold leak and its getting good fuel to the carb.....my next thing to check is the carb, maybe it has a blocked jet.....any help? thanks Jas