I have a beta techno and it has play in the flywheel in and out about 2/3 mm will this cause the probs im haven / running backwards /harsh kickback /missfire ... Now the bike wont start popping and banging but wont start. any help thanks lee ?

But surely the movement is gonna cause a prob with the stator pickup changed the key and ran fine for few hours then it came back but worse now as it wont start

Did you pull the flywheel to see if you sheared the key again?

The key looked lower on the back than the front it wont start eather all it dose is pop

Do you think play in flywheel will cause it

no in and out wont cause it ,it will sit lower to the back as shaft is tapered , i think you need to determine if key still ok ,then mark flywheel to casing at tdc and using a strobe light check the timing ( get help if no experience ) then if thats ok get a compression test done if thats ok check reeds and maybe replace crank seals if all looks ok ,, have you tried disconnecting kill switch

No not try kill switch but i fitted a new one . Loads of compression and the stator cant be advace or retarded as its not adjustable like others ive seen im gonna try another key and see wa happens thanks

But the other point is why is it killing keys if it runs wen fitting new one ??

if it has sheared again, has it been tightened enough ? has the taper or inside flywheel taper faces been damaged ? you can improve the fit by using grinding paste remove key and rock back and forth with slots half lined up

is this the same bike as in an older post by tOm541

The faces on flywheel are fine the key i removed last was a nightmare and also the new one was a nitemare to re install tight fit but run fine forfew hours then started to missfire tonight now ive cleaned all connections . And gt85 everything ill try the grinding paste see if that will make a diff thanks

You say the flywheel is moving in and out 2/3 mm. Do you mean the flywheel is loose on the crankshaft?

Or do you mean the flywheel and crank are moving in and out that far with no play between the crank and flywheel?

If flywheel is loose on the crank, keys will break. Are threading the nut on fully and using proper torque? Most bikes have a washer between the flywheel and nut. If that is missing, the nut may bottom on the threads and still not clamp the flywheel.

If the flywheel is tight and there is no play between that and the crank, yet the whole thing moves in and out, it sounds like you need new main bearings. Bad crank bearings will ruin crank seals and make the bike run poorly.

Yea mains have play so gonna have them done and seals