Carbruator

[Mjh 33]

520H ran great at full throttle. Anything less it almost sounds like running on one cylinder? So took carb off soaked it in Amsoil power foam overnight. Then blew everything out good. Sealed up intake seam while had it off. Everything back together now runs rough at any rpm. I did put a facet electric fuel pump on it a year ago. But I think probably carb is the problem? When I put carb back on intake. I didn’t have a carb to intake gasket. So used gasket maker. Could air be getting through there? I’m at a total loss on this. Last time I checked compression it was 110 front & rear. 

[pacer 3,177]

OK, this may sound -- "shade tree" but I've had luck several times with it.

 

Pull your plug wire off each side enough to let the spark 'jump' to the plug. If that cyl starts firing then your plugs are either so fouled that they wont fire, or they need changing...

 

Just a couple weeks ago my Onan started acting similar and I tried this "shade tree" diagnosis and sure enough the right cyl wasnt hitting. Pulled the plugs and gave them a cleaning and ran OK for a bit then started missing again. This time I changed to new plugs and been fine since - bout 3-4 hrs now.

[Digger 66 3,488]

1 hour ago, Mjh said:

Could air be getting through there?

 

Spray a little carb cleaner around there while she's running and listen for any RPM fluctuation .

[Mjh 33]

Thanks for info!!😄 I took carb back off & put new carb to intake gasket on. Think mabe was also leaking where intake bolts to engin? So trying a little jb weld rvt silicone gasket maker on top & bottom of gasket. Hopefully will seal it? Wanna let it set overnight so rvt sets good before cranking it over. 

[953 nut 60,071]

48 minutes ago, Mjh said:

jb weld rvt silicone gasket maker on top & bottom of gasket.

I have never used that, is tha a heat rated product?