Onan walbro carb

[john hall]

Bringing this thread back from being idle for about a year. I FINALLY got around to rebuilding the carb in my 982---needle valve not sealing. Yes its got an Onan and it has the Walbro carb--I believe it is a lua6 model. Parts are somewhat scarce, but not as pricey as you may think. The kits are priced from around $25 to $40. Apparently this is about the only kit you can buy unless you run across something NOS. There is one guy on Ebay selling a very complete kit for $155, too rich for my blood. The kit I bought has the gasket for the 2 halves, gaskets for the brass seat and main needle valve assembly, float pin and screw, idle jet/screw and spring, and some sort of foam bushing, most likely for the throttle shaft. It also includes a needle valve and the needed parts to rebuild the seat.The kit does not contain the carb or air cleaner mounting gasket.

I spent considerable time trying to find a ready to screw in needle valve. I tried searching under Onan, Cadet, and even went to my IH published parts book to get those part numbers--none of which yielded anything other than the $155 kit.

By the way, I got my kit from here:
http://vepetersen.com/
They are a Walbro dealer--give him the make and model of the carb and let them do the rest. By the way, if you look on the drivers left side, below the main adjusting jet, you will see LUA cast into the carb, mine has a 6 stamped behind that (LUA6), this is your carb model. Its right above where the carb bolts to the intake, you'll need a light, a rag, and maybe some gunk remover of your choice to be able to read it with the carb still mounted.


First off let me say I did not pull the carb from the engine--the mounting bolts are under the bottom and I was not in the mood to take half the engine apart to get to them. So I opted to rebuild it in place--besides I had an issue with the needle sealing, not a stopped up carb. First thing I did once I took the top half off the carb was to shove a paper towel down the throat in case I developed a case of "butter-fingers". Everything was rather straightforward besides the seat. This carb uses a re-buildable seat. In the bottom of the brass part we ordinarily call the seat is a rubber insert that is the actual seat. From the bottom side I carefully pushed the seat out. The new seat comes in a separate package with instructions. Basically you drop it in the brass part, make sure the orientation marks on it are correct, then press it into a small bore in the bottom--the instructions tell you what size drill bit to use. They actually call for a number drill, I don't have any here so I got the closest thing to it in a fractional size that was a tad bit smaller. I made sure the end of the drill (the chuck end) was free of burrs so it didn't damage the seat--used a honing stone to for this. Pressed in the rubber seat and then pressed in a steel retainer ring (this was not in my original set-up--maybe they feel you need it for rebuilds?). According to my dad, some Briggs engines used this set-up of rebuilding the seat, anyway I had never seen it.

Checked the float settings to the service manual (both with and without fuel in it). Set the jets by the book and carried it for a test cut--1/2 hr of overgrown grass in a hilly area we only cut with a bushhog, ran great.