Hi guys,
Just bought a non-running szr660 98 model. (Its an alloy framed sports bike with the 660 teneree engine). its the 2nd srz I have.

The bike wont start!
Ive swapped carbys between the same model- so its not carbys, (and the carbs off this bike run fine on my other srz). (had to strip them first as its been sitting for awhile and fuel had gummed it up).

Ive dropped the plug out: all valves are open at TDC.
(I checked this with screwdriver in the sparkplug hole and all the valves are loose when the timing mark on the flywhhel lines up).

My compression testers end is too large for the fitting, but when i stick my finger down the spark plug hole there seems to be good compression (so maybe no hole in the piston). also when I drop the carbs off and plug the rubber manifolds with my hand theres suction there.

one thing though there is a pretty heavy clunking sound coming from the engine when i rotate it using the starter motor. it does this more with the sparkplug in. when the plug is out theres a slight knocking but not so bad.

Its really got me stumped. Ive even tried aerostart and she wont fire. its not really a backfiring just a pushing of gasses back out the carbs. I did get it to 'pop' a back fire a couple of times but just wont run.

do you guys think this could be stator related? maybe throwing the timing out somehow? or maybe something like the key crapping out in the counterweight shaft. (Ive had this happen before but with devistating results)!
if it was stator related surely it just wouldnt fire, but should still turn over correctly. It almost feels like valves but they seem to be working correctly, and the gap seems right. maybe a stretched cam chain? broken cam chain guide? rust or carbon buildup on the valve faces?

ok im ******ed. stumped. downfounded...
any advice GREATLY appreciated..., I dont want to drop the engine out just yet!
thanks guys...

Just a thought, but is the auto decompression mechanism working as it should? Has it been replaced at some point? The unit is very easy to install upside down if you're not on the ball when replacing after a top end strip down. If it is working incorrectly or has been fitted 180 degrees out, it will give very similar symptoms to what you describe.

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I now its silly have you check the sparks.?Also remove plug cap and hold the HT wire to the top of the plug whilst turn over the motor. Check side stand kill switch.Try squirtng petrol down the carb.