Having trouble running at high throttle. Wanted to clean carburetor jets. What do i need to do? Do you use a small jet brush that I've seen advertized. ,,,,,,,,,,,, Thanks
Most issues on onans stem from poorly cleaned/tuned carbs. Speaking from experience... If it's hunting at high rpm, try adjusting the high speed screw in the carb. It is the adjustment screw towards the front of the carb (when standing on the muffler side) and should have an O-ring on the screw. I usually start at 1 3/4 turns off seat to start, and go from there. Some carbs I have worked on need over 2 turns, some need only one.
The carb for that tractor should be A DD11, and you should have a brass float in it. If it has a fiber or foam float, spend the $30 and buy a brass one. It will save a lot of issues. Also, make sure the intake manifold is sealed- it is made from two pieces of aluminum, and sometimes the sealent between the top and bottom half dries out and the intake starts sucking air, and causes it to run lean.
If re-adjusting the high speed screw, setting the float correctly, and checking for leaks doesn't fix the issue, then you can also change the hole the carb control rod goes into on the governor arm. It has three settings based on how "sensitive" the governor needs to be- sometimes as the motors wear out, you need to move which hole the rod is in. It is trial and error on that....
I have many of these tractors, and I love the onans. they can be finicky, but are well worth it when they run correctly. I have a couple that I have to tinker on constantly, but I can always fix them.