'75 850 thunderbolt won't start only back fires

[69ebkoskibee]

Finally got the starter fixed and it's now cranking at 325 rpms!!! Most life I've seen out of it yet. Primed the bulb cranked with choke and warmup forward for about 10 seconds and BAM she back fired through the exhaust? Timing is dead on to manual specs don't know where to go from here. Kind of new to 2 cycle mechanic warfare. Any and ask help would be appreciated.

 

[Chris1956]

It is cranking in the proper direction, right? Those permanent magnet starters will spin the wrong way, if reassembled incorrectly. Is the outer flywheel installed correctly? Stick a screwdriver into the top plug hole and manually turn the flywheel to top dead center. Now inspect the timing marks. They should read very close to TDC. That is a distributor model, right? Is the timing belt installed correctly?

 

[69ebkoskibee]

The flywheel is turning clockwise. When no 1 is top dead its hitting tdc on the flywheel and the dist is pointing at no 1. Timing belt is good. The distributor is freshly cleaned out and contacts look great. I'm kinda at a loss here. How do you adjust the timing on these 2cycles since you can turn the distributor?