Jumo 0 #1 Posted February 2, 2011 Near the end of snow blowing the drive today my Onan started running on only one cylinder. It appeared to be the rear cylinder. After reading a lot of posts on the forum about the valve seat problems on the rear cylinder I began to think this might be it. About two hours later for the heck of it I decided to start the motor and it ran fine. I suited up and went out to finish clearing the drive. After about 10 minutes it did it again. I definitely could tell the rear cylinder was not firing. This time I drove it back to the garage and all of a sudden it started firing. I figured it must be a bad plug. Changed the plug and it ran fine again, but ony for about 10 minutes. I decided to take it back to the garage and it began to run correctly again. I Share this post Link to post Share on other sites
repairman 7 #2 Posted February 2, 2011 I have had some problems this winter with fuel delivery to both cylinders due to icing at the carb my driveway is mostly down hill and as I push snow at an angle there are some times where this seems to be a problem I take it back to the shop where its warm and it runs fine. now in theory this should not happen due to compression pulling fuel threw the intake but if fuel isn't getting threw the carb correctly then delivery to each cylinder is compromised intake gaskets leaking (sucking air) can cause problems at lower engine RPM also. :banghead: Share this post Link to post Share on other sites
Jumo 0 #3 Posted February 3, 2011 I switched the plug wires around and the front cylinder is now missing. I think I found my gremlin. I always think of the worst and that is probably why overlook the simple things. Share this post Link to post Share on other sites
Sparky-(Admin) 19,652 #4 Posted February 3, 2011 Great news. A messed up valve seat would of really sucked. Mike.......... Share this post Link to post Share on other sites
