hi, well my son ran his trx90 without checking his oil. he said he was riding around with no problems. turned his bike off. and when he tried to start it ,it wouldn't start. so he pushed it home. when i went to look at it,i checked the oil,it wasn't reading on the dipstick. so i drained the rest of the oil out,i got about a cereal bowl full. i put fresh oil, checked to see if it had spark with the plug out,it did but i changed the plug anyway, and i drained the carb. bowl.. the bike turns over but will not start, does anybody have any thoughts on this?. and if ruined the bike because he ran it out of oil, what would we have to replace to fix it? thanks for your help.

 

If it turns over, I wouldn't think that the low oil caused a problem because the piston didn't lock up. However, if he had low oil, perhaps the oil ring is going and it's burning off some. I have a 2002 Kodiak and it never burns a drop, but my 1987 Fourtrax has always burned a little, since the day it was bought new. We were told that it was supposed to during the first XX months, but by the time we put enough miles on it and relized that it wasn't a normal thing, our warranty was gone.

Have you checked to see if the plug is wet with gas after attempting to start it? It may not be getting gas to the cylinder.

 

Check the compression and go from there.