Interesting. All my needles and jets are origonal. They look fine and I was hoping not to fork out on a whole new set. Looks like I might have to though.
The other posibility is I've got the cam timing a tooth out
. I though it a bit strange the Haynes manual says to set up cam timing and put the cambox lid on before releasing the camchain tensioner with the engine running. Of course setting the cam position with the chain slack could result in it being out of position with the chain tight.