I have fitted the 600 engine, plugged it in, without changing any wiring, or ecu/cdi and it runs! i thought i was gonna have to change the cdi, or should i still?
woody/lyod?

good work buddy! get some pictures up!

[as the stroke is longer and the rev limet is lower on the 600 i would use the 600 cdi if you trace the wires on both 600 and 400 looms/cdi and match them up you can use a 600 cdi on the 400 loom . thats the cheep way and hardest .
how dose it run ?

i only started it up and then turned it of. good point about the rpm! do you think it would damage it to rev it the same as the 400? or can the 400 handle it as it is cog driven?
i am trying to not spend any money if i can, but will if i have to.
i wont post any pics justyet as you lots bikes all look mint, and mine is a hanging mess.
i managed to bend the exhaust today using a weight lifting bench bar so the 400 exhausts now fit.
ive been told i have cut theframe in a wrong place and may have to buy another frame just to cut the little arms of!

where did you cut it pics be good . i thought i did but the welder said it was good .
to find the place to cut find a welder first and ask them as they will be welding back up .
my local only charged me for the labour £30 ph 2 hours work job done .
the 600 motor runs out of puff at 12000rpm and the 400 is 14000rpm i would use a cdi from the 600 that way it wont go pop

My 600F2 motor runs the gull CDI. I looked at getting a limiter fitted but was told by Stan Stevens "Not to bother as the stock cams run out of puff at 14K and the motor is safe at those revs."

wig wrote: ive been told i have cut theframe in a wrong place and may have to buy another frame just to cut the little arms of!

Just fabricate a new dropper arm , easy.