clueless 3,234 #1 Posted August 1, 2021 I've got this second owner '97 416-8 with the Onan well maintained 220 hr horse. when should I pull the heads and check the valve seats? Just checking so when I sell it I can tell the new owner. Share this post Link to post Share on other sites
lynnmor 7,815 #2 Posted August 2, 2021 3 hours ago, clueless said: I've got this second owner '97 416-8 with the Onan well maintained 220 hr horse. when should I pull the heads and check the valve seats? Just checking so when I sell it I can tell the new owner. That would only be a guess. The 16 HP had very few valve seat problems. Onan says to remove carbon at 500 hours and the valve seats can be checked at that time. I have never seen enough carbon to matter when I do my carbon removal, touch up valves & seats, adjust the valves and thoroughly clean the fins at 750 to 1,000 hours. 2 Share this post Link to post Share on other sites
