Staffsargeant 4 #1 Posted July 20, 2019 Looking for a carb for a Onan engine Share this post Link to post Share on other sites
lynnmor 6,762 #2 Posted July 20, 2019 Look on online auction sites or check vendors on this site. I have to ask, why do you need a carb, almost always they can be cleaned or rebuilt. Share this post Link to post Share on other sites
Staffsargeant 4 #3 Posted July 21, 2019 (edited) 15 hours ago, lynnmor said: Look on online auction sites or check vendors on this site. I have to ask, why do you need a carb, almost always they can be cleaned or rebuilt. Cleaned carb first, ran fine for a while. Back to surging. Could be fuel pump or governor or carb. Runs great on 1/2 choke. Checked with my local Toro/WH dealer, he said Governor & Carb N/A. What could be the problem? Edited July 21, 2019 by Staffsargeant Share this post Link to post Share on other sites
Tuneup 1,416 #4 Posted July 21, 2019 (edited) Not an Onan owner but from experience in this group, some have had to clean that carb a number of times before the surging ended. Maybe a can of carb soak would help. I've seen that stuff work wonders on old motorcycle carbs with their tiny passages. Your mentioning that it's good on part choke is the giveaway. More carb fun ahead! Edited July 21, 2019 by Tuneup Share this post Link to post Share on other sites
tunahead72 2,334 #5 Posted July 21, 2019 If it's running well on 1/2 choke, it sounds like it's running too lean without it, have you tried adjusting the carb? I don't know anything about the Onans, so I'll let some of the more knowledgeable among us help you. There's probably a manual here on RedSquare that would show you how to adjust the carb. Share this post Link to post Share on other sites
richmondred01 2,202 #6 Posted July 21, 2019 PM sent. Share this post Link to post Share on other sites
lynnmor 6,762 #7 Posted July 21, 2019 Pull the intake manifold and check for leaks between the two halves. Remove carb and clean it properly, removing welch plug above idle mixture screw. Replace with new welch plug, it may be in a kit or you can buy at an auto parts store. Reinstall carb and intake manifold using genuine Onan intake gaskets, not aftermarket. Use new fuel hoses and filter. Share this post Link to post Share on other sites
Staffsargeant 4 #8 Posted August 25, 2019 Fuel pump bad Share this post Link to post Share on other sites
953 nut 51,536 #9 Posted August 26, 2019 Start at the beginning of the flow path. Only runs half choked means not enough fuel. Are you using ethanol free gas? Ethanol will screw up a fuel system! Find it here. https://www.pure-gas.org/ Have you installed a new fuel line and filter, if not you should. After you have done these check the output of your fuel pump' If the fuel pump is supplying gas then rebuild or replace the carb. Don't just start out by assuming the most expensive component is the problem. 1 Share this post Link to post Share on other sites
peter lena 8,037 #10 Posted August 26, 2019 get some SEAFOAM in the gas, they also have a seafoam pressure can with a long nozzle for in engine work, really gets after the crud , at walmart for best price, that half choke sounds familuar to dirt build up and plugged jetting. i also regularly use STABIL in all my gas , no problems, an 8 $ bottle will treat 60 gallons of gas . hopefully you will make a gain letting you run with less choke , not knowing if this fuel system was ever maintained , will let you notice any gains. 953 above makes good sense to replace fuel lines, and filter , also verify if pump is pushing fuel. pete 1 Share this post Link to post Share on other sites
