Motorcycle Forum / Country Specific / UK Group / August 2007

Well the weather has gone nice again, and the bike has decided to
start playing up.

Last night when leavin work I noticed the biek would only rev upto
10k, then lurch around and
then rev through to 12.5k.

A few miles further down the road the bike started lurching at 8k as
well as at 10k and still only
rev upto 12.5k. About 2 miles further the bike was running on 2
cylinders for a bit and then died.

I tried restarting it, then with the choke and you could smell the
fuel coming through, then kicked the sidestand down and up to see if
it was the switch and with no choke it started again on 2
cylinders with the rev counter floating up and down the scale then
about a minute later it was
running on all 4 again.

The only thing that has changed is that I have replaced the chain and
sprockets, and noticing
that the sidestand switch was covered in chain grease gave it a clean.
Initially the bike  wouldnt
rev cleanly below about 5k but this went away after a day so I
thought it could have been
because the bike was left standing for a while.

Any thoughts as to where the issue could lie,  I was going to bypass
the sidestand switch and check the fuel tank breather, does this sound
electrical or fuel?

I would have thought that the only thing to cause the bike to drop a
pair of cylinders would be
losing a coil, dont know why it would then die though.

Any help appreciated.

Cheers