WD-9 Carburetor Modifications?

[Red Mercury]

I have a WD-9 that starts very well on gas but it runs very fast (1500+ RPM) which is not normal. It has been this way as long as I have had it so I decided to clean up a spare carburetor and swap them. When I took the old carburetor off the mystery was solved. It appears that the air valve (round disk) and spacer have been removed as well as a couple of other modifications. I then decided to dig deep into my spare parts and found two more WD-9 carburetors that have had the same modification. It appears that this was done to make the engine run faster and possibly start easier on the gas side. I did install my refurbished carburetor and now the tractor runs much slower on the gas side (normal). Is anyone familiar with this modification? I am wondering if it was done many years ago by a local IH mechanic in my area since I have several carburetors on hand with the same modification.


 

[WOpp]

On one of mine that disk has been cut down about 25%. An old mechanic around here said he did lots of them to speed them up a bit. He said it was recommened to him by IH dealership.
 

[red bearing]

I'm having issues with my carb...looking for a rebuild kit..do you know where I can find one that is reasonable..thanks
 

[sflem849]

[55 50 Ron]

Seems I remember you may be in Minnesota. Drop me an email. If we are neighbors, maybe I could stop for a visit. Would be fun to talk tractors, specifically the WD-9.
 

[red bearing]

sflem849 what were the symptons?that made you decide
to take carb apart? thanks
 

[sflem849]

I bought my MD after it sat in a shed for A LONG time. I think it just ran really crappy so I took it apart and sprayed it out. That was back in 04 so I have kind of forgotten what the exact symptoms were. It is still kind of touchy to get started, but from what I have read that is pretty normal.
 

[Red Mercury]

Interesting. I suspect that it IH may have been recommending that. In the carburetor I took off of the tractor, it also had the metering nozzle shortened and the small orifice in the cast iron body plugged. It worked well just faster than the normal full throttle RPM rating. It kind of worried me that a connecting rod was about to part ways with the crankshaft.
 

[Red Mercury]

I agreed with sflem849. I think Steiners sells a kit, but I doubt that it has every tiny part that an automotive kit has. The parts that are available all likely come from the same company so you won't find much difference in pricing. All of the major parts for that carburetor are expensive. I disassembled the carburetor completely and soaked it in Tyme carburetor cleaner for a couple of days to remove any gum or varnish. I bought the gaskets from Steiners for $15 and a fiber washer ($5???) from CNH for the inlet fitting. The carburetor is really simple and a kit is probably a waste of money if everything inside looks good. Most of these carburetors just need a good cleaning and a careful inspection.
 

[sflem849]

The thing is there aren't that many parts needed. A kit for one of these is only 5 parts because it doesn't have high speed and low speed jets and all that stuff.