I just bought a 87 trailboss 250 2x4 for a project and can't get it to start. It has good spark, It turns over freely, Everything is clean and good inside the carb, The airflow is clear. The carb is getting gas. After turning it over for a while it started and ran for about 5 seconds and now nothing. I am pretty sure this isn't carb related? could it be rings??? It has 120 pounds of compression so I think it should start on that. Any help will be appreciated.
Thanks

 

Has it been sitting a while? I'd drain the tank and refill with fresh gas.

 

I tried fresh gas and still nothing. Someone told me about a seal on these two strokes somewhere around the flywheel that could be bad. Anyone else think this could be the problem

 

anyone else