Hi my mates frst is pretty knackered, but im not sure where to start. the main problem as far as i know is backpressure blowing the oil cap off, but it also ended up with clouds of smoke coming from the exhaust, and oil conimg out the dump valve, im going to strip all the pipework off it tomorrow and see if i can sort the back pressure problem, but i also want to know what else to look out for.

Dougie.