You will need to remove the side cover by the shift lever and there should be timing marks on the stator. Rotate the piston to TDC and line up the marks. If it lines up then your problem is either low compression or electrical problems. Bad stator,magneto,coil,or ignition box. If you have a stock carb it needs to be pluged in because they have an over rev system that kills the bike if the throttle gets stuck. One other thing that I'm not sure about but I think they have low crankcase and low oil mixture kill as well. Check the crank fluid level and your oil reservoir. Make sure the low oil resi is plugged in. Do not use ether to try and start the bike because it could brake a ring, it could detonate and kill your crank bearings, it could even detonate and blow your reeds out if timing is off. Yea ether will help if it has low compression because thats the ONLY way to get it started and the motors worn out anyways.