Only seems to mis-fire when you give it the biggie and also when accelerating round sharp corners. I tried cleaning the plugs and the dizzy and all the usual stuff but still no luck. The exhaust also flames when it mis-fires. Any ideas anyone???

PS. The engine is running standard power...

 

try checking for loose connections , round the coil , phase sensor etc...

 

Sharp corners sounds like fuel surge!! Does it do it with a full tank???

 

Not as much, no. What should i look for?