budman2 57 #1 Posted June 6, 2019 I have a 1992 520-H wheel horse that runs great, but I just done yearly maintenance on it and found that both spark plugs are pure white! I was told that the correct plug to use is champion RS17YX gaped at .025, so that is what I am using! mower runs great but I am concerned that it is running too hot, and don't want to damage the motor,thanks for any advice in advance! robert (budman2) Share this post Link to post Share on other sites
lynnmor 7,813 #2 Posted June 6, 2019 Make sure that all debris is removed from under the shroud, not an easy job. You may have a very lean mixture caused by a dirty carburetor. Air leaks in the intake is another possibility. Either condition can be very detrimental to the engine. Share this post Link to post Share on other sites
WHX?? 51,732 #3 Posted June 6, 2019 That would be the correct plug and gap. Cooling fins and flywheel clean? Are both the front and the back jug plugs looking the same? Has belt guard been modified? Share this post Link to post Share on other sites
Achto 29,388 #4 Posted June 6, 2019 1 hour ago, budman2 said: I am concerned that it is running too hot Check for intake leaks - with every thing assembled and engine running at idle, spray short bursts of starting fluid on all intake gasket points. Also any vacuum lines. If the engine revs up when you spray an area chances are there is an intake leak there. As stated above make sure that all of your cooling fins are clean. Share this post Link to post Share on other sites
budman2 57 #5 Posted June 6, 2019 3 hours ago, WHX24 said: That would be the correct plug and gap. Cooling fins and flywheel clean? Are both the front and the back jug plugs looking the same? Has belt guard been modified? Cooling fins are clean, but haven't pulled the flywheel! both plugs look the same and have not modified the belt guard with any holes or luvers ect! budman2 Share this post Link to post Share on other sites
budman2 57 #6 Posted June 6, 2019 3 hours ago, lynnmor said: Make sure that all debris is removed from under the shroud, not an easy job. You may have a very lean mixture caused by a dirty carburetor. Air leaks in the intake is another possibility. Either condition can be very detrimental to the engine. I will check for debris and also the intake, carb is cleaned though! Thanks budman2 Share this post Link to post Share on other sites
WHX?? 51,732 #7 Posted June 6, 2019 You should not have to pull the flywheel but the shroud yes. I would mod the belt guard, Consensus is it may not help but sure can't hurt and sure better than fried valve seats. Share this post Link to post Share on other sites
Ed Kennell 41,916 #8 Posted June 7, 2019 Is the seal between the oil filter and tin shroud in place? Share this post Link to post Share on other sites
budman2 57 #9 Posted June 7, 2019 Yes it is! I will check again for debris around the shroud! Thanks for the tips guys! budman2 1 Share this post Link to post Share on other sites
