ok, so what do i need to do to sort it??

its got a power boost valve on it, so should i adjust that??

also, its got probe idling at the mo, it seems the breather from the block is collapsing, now i have replaced half of it with some much stiffer tube, but aint got enough for the rest.

could that be causing it???

it wont hold constant revs at idle, it jumps from nearly stalling (sometimes does) to about 1.5k rpm