Liberty work shop 9 #1 Posted September 2, 2022 The Onan on my 520h does this " surging thing " from time to time . Anybody have any thoughts on how to fix it ?? Thanks , Jerry ... Share this post Link to post Share on other sites
Snoopy11 5,718 #2 Posted September 2, 2022 What RPM is this mostly occurring? The idle jet tube is more often than not the issue. Cleaning is in order. The jet has small pin hole orifices and once plugged up the engine will hunt at times. Intake leaks can also cause this... and the best way to check is to spray carb cleaner around the intake side... if the engine changes pitch in any way... you have a leak. I only recommend doing this on a cold engine though... Don 2 Share this post Link to post Share on other sites
Snoopy11 5,718 #3 Posted September 2, 2022 Also an asset: https://www.wheelhorseforum.com/topic/85330-520-h-onan-surging-issue/ Don Share this post Link to post Share on other sites
Liberty work shop 9 #4 Posted September 11, 2022 Well , I decided to do what many others have done , and that is to replace the carb ... I do have one question though ... The intake manifold on this is two piece ? When i'm cleaning things up , should this be taken apart and resealed ? If so where can I find the gasket for it and what holds it together ? Thanks , Jerry ... Share this post Link to post Share on other sites
lynnmor 7,813 #5 Posted September 11, 2022 2 hours ago, Liberty work shop said: Well , I decided to do what many others have done , and that is to replace the carb ... I do have one question though ... The intake manifold on this is two piece ? When i'm cleaning things up , should this be taken apart and resealed ? If so where can I find the gasket for it and what holds it together ? Thanks , Jerry ... There is a thread right above yours detailing how the intake manifold can be sealed, look for the .PDF file. Gaskets can be purchased from onanparts.com, do not use anything other then genuine Onan gaskets for the intake, some cheap Chinese gaskets deteriorate within a year. We don't replace carburetors with cheap Chinese junk unless there is no other option. 1 Share this post Link to post Share on other sites