twodogs 55 #1 Posted March 4, 2019 I have a 1991 Wheel Horse model 520H with the P220G Onan engine. I bought it used and it has run quite well until recently. It has 350ish hours on it and it has started to run a little rougher than when I first got it, and it is starting to surge. I decided that I'm going to take the carb apart to give it a good cleaning, and that I might as well adjust the valves as I doubt they've been touched since it was assembled. With those tasks in mind, I was hoping to have all the "required" parts available when I begin the work, so that I'm not faced with downtime. Could someone knowledgeable with this process please let me know if I'm on track for the correct gaskets, and if there are other parts that I should just replace since, "I'm in there"? I also plan to remove any carbon from the heads. Thanks much for the input and here are the parts I imagine I'll need: 110-3709 Valve cover gaskets (2 required) 154-2495 Intake Manifold gaskets (2 required) 154-2746 Exhaust gaskets (2 required) 110-3181 Head gaskets (2 required) Share this post Link to post Share on other sites
Shynon 7,482 #2 Posted March 4, 2019 @boomers_influence will have everything you need Share this post Link to post Share on other sites
WHX?? 51,787 #3 Posted March 4, 2019 or @onanparts.com the proprietor of that site has a kit put together with all the required gaskets give him a call... real good guy. 350 hrs sounds kinda low, any chance the hour meter is not working or been changed out? 1 Share this post Link to post Share on other sites
lynnmor 7,828 #4 Posted March 4, 2019 (edited) If you are going that far, I would pop the valves and check for loose seats. Check the condition of the surfaces to be sure that a valve grinding isn't necessary. Assemble with new intake valve seals. Glass bead the exhaust and paint with header paint or Rustoleum high temperature paint. Be careful with tightening the manifold bolts, they strip easily, I tap deeper and use slightly longer bolts. So my list adds: valve seals paint longer bolts Never Seize Be sure to check for leaks between the two halves of the intake manifold. You will need sealant, small screws, washers and lock nuts to fix. Edited March 4, 2019 by lynnmor 1 Share this post Link to post Share on other sites
