fishingstararlake 1 #1 Posted July 21, 2015 took my 520-h with 1000 hrs in to get looked at. They called to day and said the back cylinder was down on compression.they asked me find a gasket kit to do a valve job. he is closed now and I'm not sure what he needs and I would like to get it on order.I'm thinking this is what he needs VALVE GRIND HEAD GASKET.This is a older guy that was a WH dealer he is the only one that has any experience with onans.I said I would look for parts for him (he does not like computers) is there gaskets or parts I should stay away from.any help would be very appreciated Dan Share this post Link to post Share on other sites
bmsgaffer 2,043 #2 Posted July 22, 2015 Im going to tag @boomers_influence into this post. He deals in all the parts you are looking for. Share this post Link to post Share on other sites
boomers_influence 106 #3 Posted July 22, 2015 danplease call me 651 437 2826M-F 10-7 S-S 12-6 cent time zone.please have the spec# from the engine tag,located on the cowl. ( fan cover )thank you. boomer ( the used onan engine parts guy, also NOS and new ) Share this post Link to post Share on other sites
546cowboy 301 #4 Posted July 30, 2015 I hate to be the one to tell you this but if the guy hasn't torn that down yet, you may need a new valve seat. It's a common problem because of owners who don't do the cleaning or maintenance they should. You will find plenty of articles on here about that. I have had four of them with the valve seat loose on the rear cylinder. I buy them that way and repair them. Share this post Link to post Share on other sites
fishingstararlake 1 #5 Posted July 31, 2015 I,m out of the country now so I have not had any contact with him in over a week now.I was thinking the same thing. what is the best way to fix it. Share this post Link to post Share on other sites
fishingstararlake 1 #6 Posted September 8, 2015 Just got done mowing for the second time after getting my 520 back.runs great now. Ended up having a lose valve seat. had a local machine shop turn a new one and touch the other ones. Share this post Link to post Share on other sites