Mine has a pile of hours on it (5500+) but still runs "ok". When started cold, it seems like it fires on 2 cylinders and the third starts to fire about 30 sec to a minute after starting. Any ideas there? When warmed up and running, it runs well, but just seems like it could have a little more... It's in a 643 Bobcat and I'm pushing a 7 1/2 snow blade with it.