16 Hp onan Surge

[scotty 252]

Ive got this 416h that i can not get to stop surging. Ive cleaned the carb several times thoroughly. It runs good until the engine gets warmed up. Any ideas what could cause this? Ive replaced the fuel pump and fuel filter, Nothing seems to help.

Edited September 11, 2016 by scotty

[gwest_ca-(File Mod) 11,267]

Is it a surge or governor hunting?

Garry

[scotty 252]

Hmm never head of that. It might be. I may have to try that. Thanks for the info.  I also see somthing that looks like a condenser. Could that also cause the hunting or surging? This has the p216

Edited September 11, 2016 by scotty

[GMan 82]

Scotty,

 

It is not at all uncommon for the Onan's to develop the "surging" when the gasket material on the inherent two piece intake manifold fails with age. These can be repaired by removal of the manifold, splitting it at the seam, cleaning off all old gasket material and re-sealing it with the grey Permatex sealant that is impervious to gasoline. When doing this you need to drill out the locating pins of the stock casting and bolt the two halves back together with small screws and nuts and wait 24 hours for the material to cure before putting the manifold back into service. This is not difficult to do, it just takes time. Boomer who is the resident Onan expert here also has replacement manifolds both new and used at more than a fair price.

 

I have also experienced the small plug on the front of Onan carburetors coming loose, falling out and causing "surging". It is easy to visually see if that is the case although not so easy sometimes to find the plug that has come out.

 

A third place to look is to pull the top off the carburetor to check for dirt inside that can block passages within and cause "surging".

 

Hope this helps....................Gary