1990Onan520-H 15 #51 Posted February 4, 2020 31 minutes ago, Mudrig150 said: Should be pretty easy, just tedious. Remove valves or get something to hold them open, push the tappets in, and then you should be able to just pull the cam out. If need be, pull the gear off. We only own 2 B-series, but that should be the process. Well valves and timing cover are off already anyway. So governer off and i guess there is some kind of retainer to hold the can in or does it all just slide out? I'm not near the engine or service manual at the moment so just curious. Share this post Link to post Share on other sites
Mudrig150 298 #52 Posted February 4, 2020 (edited) 3 minutes ago, 1990Onan520-H said: Well valves and timing cover are off already anyway. So governer off and i guess there is some kind of retainer to hold the can in or does it all just slide out? I'm not near the engine or service manual at the moment so just curious. I think- Don't quote me on this, that it just slides out. It's like a car camshaft. Should've been held in my the cover. Edited February 4, 2020 by Mudrig150 Share this post Link to post Share on other sites
1990Onan520-H 15 #53 Posted February 4, 2020 2 minutes ago, Mudrig150 said: I think- Don't quote me on this, that it just slides out. It's like a car camshaft. Oh well that would be nice. I'll take a look this weekend. Maybe do that before pulling pistons because if the cam bearings are shot it's done. Share this post Link to post Share on other sites
onanparts.com 178 #54 Posted February 5, 2020 13 hours ago, 1990Onan520-H said: Oh well that would be nice. I'll take a look this weekend. Maybe do that before pulling pistons because if the cam bearings are shot it's done. Lifters/tappets all need to be removed before pulling the cam. If the cam bearing at the gear end is good, you will destroy it if great care is not used when pulling the cam out. The P220G has a high lift cam, and will only come out nice and easy if in correct position/positions, relative to the open/notched area of the cam bearing. If force is used at any point during removal, what might be a good cam bearing will be toast..... 1 Share this post Link to post Share on other sites
1990Onan520-H 15 #55 Posted February 6, 2020 On 2/2/2020 at 3:08 PM, bcgold said: Would like to see some pictures of those pistons. Here's the piston from the damaged cylinder. No rings are stuck in either cylinder and rod journals look great. Wrist pins tight and all clips in place. Lifters are also free to move. I'm wondering if this gear play is normal and the tap was out of adjustment valves. At this point I think I'm going to buy all new gaskets and seals and throw it back together hoping for the best. The engine seems to be in decent shape for 1000 hours and 32 years. 1 Share this post Link to post Share on other sites
troutbum70 857 #56 Posted February 7, 2020 Looks like you have been on what Trump calls a witch Hunt. Had you during your journey done a valve tappet adjustment? Share this post Link to post Share on other sites
1990Onan520-H 15 #57 Posted February 7, 2020 1 hour ago, troutbum63 said: Looks like you have been on what Trump calls a witch Hunt. Had you during your journey done a valve tappet adjustment? Not yet, but I will be doing one. They were out of spec for sure. Intake valve had zero clearance and the exhaust I believe too much. Cleaned out the piston rings, although they were not in bad shape at all. Going to order a complete gasket set tonight to reseal it all and toss it back together. Just going to hope she has another few hundred hours left in her. I put the pistons back in tonight too so reassemly has started. Also as a side note, when I pulled the pistons out there was no ridge. They came out no problem. Share this post Link to post Share on other sites
troutbum70 857 #58 Posted February 7, 2020 Best of luck may it live on for many more hours. Share this post Link to post Share on other sites
1990Onan520-H 15 #59 Posted February 12, 2020 Well... just ordered the rest of the seals from onanparts.com (re-gasketing/sealing the entire engine and doing a full de-grease on it). Decided to get the valves ground also. I'm already into it around 200 bucks, so why be stupid and do things half way. Hopefully the gear play is normal and the tap was out of spec valves or heck, maybe something in the belt system was resonating and making me think it was an engine tap. As soon as I get the gaskets in I'm going to toss it back together and hope for the best. 1 Share this post Link to post Share on other sites
