I'm really at a loss.
last week the bike (04? xtx with powercommander fitted) was showing signs of a bad plug, cutting out at higher revs.
I changed the plug and checked & sprayed all the connectors with WD40. then it got worse! I swapped out the coil and plug cap. but now theres no spark at all. tried bypassing the side stand switch but still no spark. when it did have spark I could only just get it to start by covering the airbox inlet to hand choke it. Ive tried swapping the sensor in the airbox but makes no difference. when it did run it would cut out at low revs and the huge backfire has me stumped!

Im wondering if the ECU is cactus. or could it be the powercommander? Ive tried 6 different plugs, 2 different coils. I'm running out of options!

oh, and im in Asia with no mechanical support!
wwwwaaaaaaaaaahhhhhhh!

any advice would be GREATLY appreciated!

I have just had to replace the fuel pump on my 09 XTR..
Might be worth checking it...

but it dose sound like it's prob spark...

If it is the pump theres a cheaper option than Yamaha offers
by replacemant of the whole pump unit....
like $800 cheaper...

__________________
Harley Davidson..
The easyest way to turn gasoline into noise with out the side efect of horse power...

Try to disconnect the powercommander and see if that is the problem.