homegrownusa 4 #1 Posted June 27, 2020 I have a 1989 520H with 20 Hp onan. The engine has had several issues around vacuum leaks and magnets coming off magneto. Waiting for pressure checker to come in to validate no other issues. My question is does this Red Square Forum have any experts on the Onan who rebuilds them blind folded? Like someone that specializes in rebuilding them... If compression doesn't work out I would be interested in rebuilding it to keep the machine original. I know...$$$$$ Thank You Share this post Link to post Share on other sites
horseyheaven 113 #2 Posted June 27, 2020 I rebuilt mine myself with parts from Onan parts.com. Great resource for parts. I am not looking to rebuild yours though. Mine did not need any machine work, just new rings, bearings, valve seals and oil seals. It did not cost much at all. I thought parts were fair priced myself. I have spent more on Kohler parts to be honest. You might try calling local dealerships near you to see if any mechanics or retired mechanics are interested in rebuilding them. I really like the Onans so far. They have a sound of their own. Share this post Link to post Share on other sites
bc.gold 3,403 #3 Posted June 28, 2020 Both my Simplicity 9020 and Alice Chalmers 720 tractors have the older Onan CCK engines made from all cast iron, I have a spare engine block from the same 1975 birth date. Absolutely no cylinder wear evident in the spare and my 9020 for the past three years has been used to blow snow from a very long driveway and make walking trails on our two acre property. Living in Central Canada we get plenty of snow. I think Onan used a superior metal alloy in their engine castings, and would expect the same quality in their cylinder liners used in the aluminum blocks. Share this post Link to post Share on other sites
