When i go out and ride for over 20 mins all of a suddern when i slow for traffic lights or a roundabout the revs just drop to 0 and i can smell petrol. It bumps and restarts on button but its very scary when turning right in traffic and it cuts out.Any ideas??

I'm sorry but I believe you have this posted in the wrong product category. Please re-post the question in the proper category This is the car and truck problem category

It could be your MAP sensor.

Do you have any codes?

but is the fuel going to carbs or injectors--also chec fawcett at tank--if theres a fuel pump it may be failin--those hispeed spurts consume much petrol no wheelies

The first thing you do is have the engine control module scanned for fault codes. I also suggest you buy a can of spray throttle valve cleaner and clean the throttle valve and the idle speed control valve.

MAN ITS A MINOR PROB JST CHANGE THE SPEED OF COMBUSTION IT SHOULD BE 1 MIN AT UR RPM METER IN THE BIKE AND ITS PIN IS NEAR THE CARBURATER JST CHANGE IT AND ENJOY UR RIDE

You need some new head gaskets, my friend. Or you have a cracked head... either one = BIG BUCKS. bummer.

did you change the screen with the oil pump?
sometimes the screen will get clogged up and lose oil pressure.

That sounds like your alternator might need to be replaced.

Check out the rubber/metal flange that joins the carburettor to its manifold. Wait while the engine is cold. Then check if the carburettor moves . Do this by taking hold of the carburettor and moving it a little side to side. The rubber mounts are known to perish after a time and this can cause air to be sucked in through the cracked flange rubber and in turn causing the engine to drop revs. The flanges are a replacement part and not too expensive so its a relativley easy fix if this is the problem.
GOOD LUCK