Onan help needed

[MalMac 1,328]

Ok, after many attemps at solving the surg problem I have replaced the carb with a new one. Now I have no surg just rough running and black sooty exhaust. Not knowing enough about the Onans I am at a loss as what to check. If it were a Kohler I would say the carb just needs a little adj. From what I read in the shop manual there is not too much you can adj. on the carb. I need some help from the Onan guys or gals out there. Also just a little info on whats been done so far. I did clean the tank, new fuel line and fliter. Also from what home made test on the fuel pump I did said its doing what it should be doing.

[sorekiwi 761]

I dont know the answer, but I'll throw a few ideas out there...

I assume the air filter is OK?

Breather isnt pumping a whole lotta oil into the aircleaner?

No airleaks in the inlet manifold? This would normally cause the engine to run lean, but its not unheard of to find the 2 piece Onan manifold leaking.

[Polaris2007 4]

My brother in law just brought home a John Deere 316 with a 17hp onan, and the governor was "hunting" or surging badly. At my advice, he took the carb off, cleaned it, put in a rebuild kit, put the carb back on, and the problem was gone. That thing runs like a champ now.

[Buzz 502]

Here's the link to Yahoo's Onan Engine Club.

http://groups.yahoo.com/group/Onan_Engine_Club/

I'm not taking away from the expertise of the Red Square members, but there may be someone in the group who had the same problem. I'd join it. The more help the better. If someone there can solve your problem please share it with us.

Good luck.

[Pettybilt 3]

I have a 416-8 with an onan, and it has an idle mixture screw that makes a big differnce, however from what i understand it only effects the idle, anything above an idle then the jets are controling the mixture. If your problem is above idle, then i would make sure the jets are the same size as whats in the old carb, other wise the idle mixture screw should take care of it. :)