So, firstly thanks for all the help so far....
I got some fresh gas (petrol) 93 Oct, mixed 64:1 with Silkolene 2T premix. Checked the plug had a spark (yes) but the gap was 1mm. I changed this to Sherco's spec of 0.6mm. Incidentally the plug was dark brown on 3/4 of the insulator and tan brown on the other 1/4. Looks like the jetting is close, maybe a little rich top end (ok)? While the plug was out I kicked it over 3-5x WOT. Removed fuel line from petcock and checked that fuel flowed out.
Put the bike in 2nd with choke on and WOT, rocked the bike over a few times.
Neutral,
throttle closed, no start.
1/2 throttle no start,
WOT, no start
....mmm.....
Pulled the plug again...DRY!
OK, so it appears I have a fuel problem between the petcock and the combustion chamber. Any ideas? Should I drain the floatbowl? Remove the carb? Maybe I stuck the floats laying it down? Is the carb easy to take off?
Thanks,
Jon.