Walbro carbs

[jsdogg99]

so why does my 75 JD 300 say it suppose to have a WDA-31 but its marked WDB-31, i bought a diaphragm kit from newbreed, for the WDA-31 is this still going to match up and work? also any pluses performance wise going to tillotson (not sure of the model that would fit) or mikuni V34. also any bolt on kits available?

[Steven Rempel]

I wish I could answer your question better. I to have notice this on a few of my sleds as well. it will run with either one. I some were read that one of them has better mid range response but I cant seem to find that post. I am pretty sure that wda kit will work just fine. Just take care in following the specs for tuning and adjustment of the needles and stuff. I found that some kits will not work when you follow the old original specs and some work great. it will depend on the thickness of the gasket material. Most of all my issues with the walbor end up in the needle arm adjustment.

I am not aware of any bolt on kit to change over to a mikuni for the 300 but there are a few that have done so and there are posts regrading that and all the mods needed.

[Matt]

There were minor carb P/N changes over the years. All the Walbro rebuild kits on JDs are are all the same so you should be fine with that. A Tillotson won't be any better as far as performance. A Mikuni might do better but requires you to try jets, test run it, change jets to re-adjust, etc. You can't just throw one on and ride. A swap would require a rubber mounting flange, fuel pump, choke cable, throttle cable, and modified or newer hand grip because the throttle lever needs more throw to get the Mikuni wide open.

[jsdogg99]

sounds good, and i did order a diaphragm kit from you guys matt, who ever owned my jdx before me put a tillotson on it and it seems to run fine, but i would like to put a stock WDA-31 back on it, any ideas of where to get one with a silencer?