I got a 91 Trail boss 250 that had a burned up piston. i put a new one in but i dont know if the oil injector is working. that may have been why the piston went bad. what i want to know is can i just mix the oil in the gas at first to make sure the motor works properly before i jump the gun and buy a new oil injector? any help would be great. thanks

 

alot of times when they rebuild 2 strokes they premix the gas/oil for the first tank as well as the oil injestion. when you say burned the piston, what do you mean? did it burn a hole in the top of it or did it melt the slides to the rings? alot of times if the oil injection stops it will seize the engine and the crank bearings. burning the piston is usually due to too much air or a lack of gas, or running too hot of a spark plug.

 

when i took apart the motor the piston was black from the rings on up. the cylinder walls werent scratched much.

 

sounds like it had carbon build up. did you do a compression test before you rebuilt it to see if it needed it.

 

when i got it it did not run. who ever had it before me tried to take the motor out because when i pulled it there were motor mounts missing.