Callen 64 #1 Posted June 19, 2012 My 520 has an Onan. It has the crank case breather like the P224 but has 9 head bolts like the P220, info from Onan Manual...So can anyone tell me which engine this is? The engine was replaced at 700 hours. Share this post Link to post Share on other sites
MarkPalmer 80 #2 Posted June 19, 2012 As I've come across several different styles of breathers used on Onan engines regardless of their power ratings, I would say the 9 bolt heads would make it a P220. -Mark- Share this post Link to post Share on other sites
JackC 616 #4 Posted June 21, 2012 I believe the P224 has 10 head bolts so it would not be a P224. Share this post Link to post Share on other sites
