6wheeler 668 #1 Posted June 14, 2014 Hi all.I have yet some more questions. How does a guy peen them. My 520 finally gave up the ghost yesterday. I took it apart and outside of the seat being loose? All looks very well. Even with 1055 hours on the clock, I can still see crosshatching on the cylinder walls and no ridge. I am impressed. Also, has anyone tried JB weld lightly around the outside to keep it in place? Maybe some exhaust sealer or something like that to basically glue it in? Also, does anyone have the valve adjustment specs? I don't think these have ever been done. I wonder if keeping them adjusted may even solve this problem. Or,at least help. Thanks Pat Share this post Link to post Share on other sites
boovuc 1,090 #2 Posted June 15, 2014 Fundamentals of "peening" a valve seat. If you google....."P220 Onan engine" then type "Service Manual", you should be able to find a service manual for the Onan P series for a John Deere tractor that is downloadable. It has the specs for valve adjustments in the manual. Share this post Link to post Share on other sites
546cowboy 301 #3 Posted June 16, 2014 (edited) Never been a fan of peening valve seats. That is something an unscrupulous owner would do and turn around an sell it to an unsuspecting buyer. The only sure repair is to pull the motor and go to a good machine shop and have an oversized seat installed. I just posted a link last week to the Onan site with what they have in oversized seats. See "Valve seat help?" further down here. Edited June 16, 2014 by 546cowboy Share this post Link to post Share on other sites
boovuc 1,090 #4 Posted June 16, 2014 I agree Cowboy. Especially with these Onans! Question was how one goes about peening a valve seat and there you have it! Share this post Link to post Share on other sites
wrmhaste 235 #5 Posted June 16, 2014 Adjustments are 5 thousandths on the intake and 13 thousandths on the exhaust. I just did the same procedure on mine few weeks ago. Share this post Link to post Share on other sites
6wheeler 668 #6 Posted June 16, 2014 Thanks for the help guys. And 546cowboy and boovuc? I am going to peen the seat. Just because I want to try it. Unless this tractor literally goes to hell in a handbasket? It will never be sold. If it doesn't work? Then a Re-Power will be in order. I use stuff until it can't be used anymore and then ladies and gentlemen. It becomes a parts donor. 2 Share this post Link to post Share on other sites
Red-Bovine 334 #7 Posted June 17, 2014 I peened the valve seats in my '92 Onan. It worked fine, but after the first valve went I had a second one go (other cylinder). I repaired that and finally a third valve seat went. Then I just repowered with a Honda GX630 from Repower Specialists in Oregon. You should get a couple of years out of the repair, but it is not totally permanent. My seat was pretty loose on the first one. I could not find a seat close enough to match the clearance needed, so I wrapped a layer of metal flue tape around it, popped it in (was snug), ad peened per the example above. Love the Honda!!!! Red Share this post Link to post Share on other sites
