XTZ660 1993 No startup but backfires

[untertaber]

Hello, ive been working on my tenere. I now have spark and fuel it seem.. but the bike still doesn't start, beside the occasional backfire. Could it be that the ignition timing is out of spec?? Is this a hard job to do? Thanks!

[dzl]

So you have a consistant spark when cranking? First pull the air filter out and spray aerostart in airbox. Does it start? If yes then likely have carb issue and/ or intake manifold air leak. If still no start then check valve clearances and then cam timing. Remove cam chain tensioner. Is the tensioner piston fully extended when you remove it? If so, cam chain may be stretched and may have jumped a tooth but unlikely.

[untertaber]

Hi, I will do. Valve clearance are in spec, doubt the cam chain is the issues.. bike ran fine for a while.