Engine runs well and would tick over for ever but under load it lasts about 5 minutes and then dies and will not restart.
I bleed the fuel system through and turn the engine over for 30 seconds and it slowly kicks back into life but after 5 minutes under load it dies again

I assumed fuel starvation so I:
Cleaned out the fuel tank
cleaned the separator
Cleaned fuel pump and filter
Fit new Fuel filter
Blasted 120psi of air through all the hoses
Fit new air filter

Big Hal, March 2010

I would suspect the lift pump. Check the operating arm and pivots for wear. Check that the diaphram is sound and that the pump is delivering sufficient fuel at suitable pressure.
I had similar problem with my m/c. Would run normally, then begin to die finally stopping due to airlock. A new lift pump cured it. Not expensive, £18 about 5yrs. ago.

Mr.Toad, March 2010

Have you tried running it with the fuel tank cap off? Perhaps the breather is blocked?

don, March 2010