JackC 617 #1 Posted February 23, 2014 A friend has a Kubota diesel that is starting hard in cold weather. My experience with Mercedes diesel engines tells me valve adjustment is key to easy starting in cold weather. I have found that engines that would not start in cold weather, easily start at zero degrees after a valve adjustment and without using the block heater. The reason is the temperature of the air in the cylinder is raised significantly when it is compressed. It is the hot air that ignites the fuel. The purpose of the glow plug is to help raise the temperature of the air. The glow plug does not ignite the fuel. The hot air does. If the valves are not properly adjusted the air will not be compressed sufficiently to reach the high temperature needed to ignite the fuel in cold weather. Proper valve adjustment is also important for the longevity of an engine. Valve adjustment on garden tractor engines is often neglected until the engine does not run properly any more or the engine destroys itself. Here is a publication from Caterpillar that explains why valve adjustment is important. I believe the ONAN Performer series engines have gotten a bad rap partly due to owners neglecting valve adjustment. 1 Share this post Link to post Share on other sites
Desko 623 #2 Posted February 23, 2014 I think that is why the seats come out because they are out of Adjustment and is holding the seat valve open so when it shuts off the seat pops out from uneven cooling Share this post Link to post Share on other sites
Fordiesel69 271 #3 Posted February 24, 2014 That and poor cooling. The 60" deck will sling all kinda of grass into the flywheel. Share this post Link to post Share on other sites
Desko 623 #4 Posted February 24, 2014 So will the 42-48 if there side discharge Share this post Link to post Share on other sites
