Thank you Mark
I bought it not running, did set the valves and cleaned the carb - still not running.
I have a Yamaha 660 project that I did have to change the chain and cam timing gear along with a bunch of other stuff - it was no fun so I was wondering about the 300. The 300 timing chain looks worse to do.
Seems like I'm not the great mechanic I thought I was.
Rephilracing suggested that I do a compression check. It has no front deck and the gas tank was off, so I took the carb off the engine intake for the compression check
Compression was 150. I had cleaned the spark plug previously and neither time I took the plug out was it wet, couldn't smell fuel in the exhaust either.
I poured a little raw gas into the intake and it started right up. I ordered an Amazon carb to check my theory, then I'll go back and rebuild the original carb properly.
It's nice to know these run with old timing chains, they have a good reputation for toughness.