muz123 1,182 #1 Posted July 11, 2018 (edited) This is an odd problem as it seems the tractor overheats or could be a governor problem. So when i start mowing with the 518 for about 20 minutes it runs good but then after about some time it starts revving very high when the throttle is moved up or down. When i move the throttle up a little bit the engine does a really high rev. When i try to engage the mower deck again the engine revs high over than it should be. I drove it around for about 20 minutes and ran fine but soon after it started doing the very high revs with no attachments engaged or on the tractor. I have cleaned the carb out 3 times, pulled the whole carb off and cleaned it good. Sprayed out the gas tank and even put a new fuel filter on and added a gas treatment and higher octane gas and no luck! Is it a governor problem? any adjustment for it? Any ideas what could be solution? I'm running out of ideas. Thanks Dave Edited July 11, 2018 by muz123 Share this post Link to post Share on other sites
boomers_influence 106 #2 Posted July 11, 2018 muz make and model of engine, please. thank you. boomer Share this post Link to post Share on other sites
muz123 1,182 #3 Posted July 12, 2018 2 hours ago, boomers_influence said: muz make and model of engine, please. thank you. boomer Onan p218 Share this post Link to post Share on other sites
Bill D 1,577 #4 Posted July 12, 2018 Sounds like you have the usual Onan governor problem. My P216 has the same problem. I haven't fixed it yet as it is not my main working tractor, and I have been trying to sell it anyway as I want to stay away from hydros. The My Tractor Forum has thread titled Onan Governor Flyball Spacer Fix that explains how to fix this problem. Talk to Boomer before you try it fix it as the thread does have some mistakes in it. Boomer is a wealth of info and should be able to supply you with the necessary parts to fix your engine. Please post a picture of the engine ID tag as it does have information that will be needed to diagnose and obtain parts. Please take pictures of the reapir and post them when you fix the engine. Good luck. Bill 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,444 #5 Posted July 13, 2018 The info we have on the 518-H 1988 518-H tractor model 31-18OE01 uses P218G-I/10539A 1989 518-H tractor model 31-18OE02 uses P218G-I/10539B Garry Share this post Link to post Share on other sites