chuck 0 #1 Posted April 11, 2012 Can someone please help with this. My 520H with 606 hours is blowing gas out top of carb. Started having problems last summer..a friend thought he would help by adjusting the carb...bad idea! the real problem was blown head gasket,now that head gasket is replaced,valves adjusted by a pro to onan specs i cant get it to run at max rpm with air cleaner on and as mentioned its blowing gas. Share this post Link to post Share on other sites
CRE1992 135 #2 Posted April 11, 2012 Sounds like the valves need to be readjusted. Onans will spit out gas if the valves aren't adjusted right. They might be adjusted to spec, however due to be worn the might need to be adjusted by a few thousands of an inch. Share this post Link to post Share on other sites
chuck 0 #3 Posted April 11, 2012 Ok thanks, I was thinking that could be a reason. I also just discovered a electrical problem in the fuse block. Under the hood there is a block of three fuses a 15,25,30 amp i push down on the middle one (25 amp) and the engine speeds up and ran smoother...not sure but could that be part of the problem also? Share this post Link to post Share on other sites
CRE1992 135 #4 Posted April 11, 2012 check to see If the battery is being charged when then engine is running, stator problems can cause it to run rough also Share this post Link to post Share on other sites
