crazy passworD 3 #1 Posted July 24, 2021 Well i have new rings,new coil, ignition trigger and now i need to work on the valves.Should i get new valve stems or is it ok to reseat the valves with grinding compound.i know i will need new seals.when i had the heads off they didnt look that bad.It is 30yrs old with 1100 hrs and runs rough..Help me decide.Thanks in advance Glenn Share this post Link to post Share on other sites
squonk 43,780 #2 Posted July 24, 2021 What engine are you working on? Grinding compound removes very little.Best to have a machine shop grind or replace the seats. Share this post Link to post Share on other sites
crazy passworD 3 #3 Posted July 24, 2021 18 minutes ago, squonk said: What engine are you working on? Grinding compound removes very little.Best to have a machine shop grind or replace the seats. onan p220g Share this post Link to post Share on other sites
lynnmor 7,813 #4 Posted July 24, 2021 I guess that you are working on that P220 Onan. Check that the valve guides and valve stems aren't worn, replace as needed, they usually can be used. Then grind the valves and the valve seats, I am not a fan of lapping because it doesn't restore the angles and seat width. Share this post Link to post Share on other sites
crazy passworD 3 #5 Posted July 24, 2021 2 minutes ago, lynnmor said: I guess that you are working on that P220 Onan. Check that the valve guides and valve stems aren't worn, replace as needed, they usually can be used. Then grind the valves and the valve seats, I am not a fan of lapping because it doesn't restore the angles and seat width. So it would be best to get new valve stems ,have valve seats ground and check everything else Share this post Link to post Share on other sites
lynnmor 7,813 #6 Posted July 24, 2021 Just now, crazy passworD said: So it would be best to get new valve stems ,have valve seats ground and check everything else The small part of a valve is its stem, if that is worn the valve needs replaced. The hole that the valve stem rides in is the valve guide, if the hole is worn too large the valve guide is pressed out and a new one pressed in. See your Onan Service Manual for procedures and wear limits. Share this post Link to post Share on other sites
crazy passworD 3 #7 Posted July 25, 2021 Thanhs i will my neighbor is always working on his race car and said he would help me with this .Im 79 so alot of this is new.I appreciate all of your help.Thanks again Glenn 1 Share this post Link to post Share on other sites
