i have a 1996 250 trail boss that has been getting harder to start with my electric starter and now wont start unless i pull start it ( about 15 pulls to start) The starter sounds like its turning the motor over good but wont start and i have to pull forever . I took carb off last night and cleaned still no change o yea new plug to. PLEASE help what has gone bad ?

 

i would say stuck rings if it was a two stroke but i dont know about a 4 stroke but i would asume that its the same

 

Sounds like it is time for a topend rebuild.