dwcphoto 7 #1 Posted May 26, 2014 Hi Folks, Two questions for you. My 518H (onan 18) has been running quite well, thank you for your help. Today, while mowing, I turned it down to idle with the mower off to move something. I'd been running it pretty much wide open for at least an hour at that point. I noticed it was surging a little bit. When I started mowing it was fine. When I ran it at idle when I was done for a warm down it was smooth as butter. Ideas? The other things is the clutch. Should it spin when it is not engaged? The mower stops, but when there is no belt on it, it spins. I thought with some hand pressure the pulley would stop, but it's pretty strong. Is it simply adjusted too tight? Thank you, dwc Share this post Link to post Share on other sites
smoreau 658 #2 Posted May 26, 2014 Spinning is normal with no attachment on the tractor. There is a brake to stop that, but most of the time it is out of adjustment. As for the surging it needs the top of the carb pulled and the bowl cleaned out. Both are not out of the ordinary problems Share this post Link to post Share on other sites
Martin 2,131 #3 Posted May 26, 2014 (edited) here we go again........ and there are many others, just search Onan surging, Onan carb problem, tons of reading on the subject and solutions too......... as far as the clutch goes, mine spins a little when no belt on it, the brake needs adjusting if this is the case, i don't worry about it too much, but there is a bracket that bolts to the pto upper bracket that has friction material on the back side of it. when the clutch is disengaged the bell of the pto rests against it and if adjusted properly it will keep the bell from rotating with the engine...... Edited May 26, 2014 by Martin Share this post Link to post Share on other sites
dwcphoto 7 #4 Posted May 26, 2014 Thank you very much! I'll take a look at the posts and take a look for that brake. Much appreciated! dwc Share this post Link to post Share on other sites
jdleach 525 #5 Posted May 26, 2014 I do not know if there are different specs. for each engine, but the K series Kohlers require that you engage the clutch, then place a .012" feeler gage between the clutch brake and pulley face, then adjust and tighten the brake. 2 Share this post Link to post Share on other sites