Allis WD45 TSX 464 Carburetor

Good Evening,

I am completely lost here and would appreciate any help!

I have an Allis WD45 that is sporting the Marvel Shebler TSX 464 Carburetor. Here is how this all started.

I went and hooked up my snow blower and parked the tractor in the yard waiting for the snow to come. Nothing until after Christmas. When I went to fire the old girl up she ran fine and was blowing snow for about 10 feet worth and started running like crap. So i didn't have the tractor stuck in a weird area blocking the driveway, I parked it off to the side. I had a friend that said he knew a lot about carbs. He pulled it a part and we found gas was being retained in the float so he was pretty confident that was the problem. I ordered a new float and needle / seat. He put it together and "cleaned it" (i probably should have just put a new kit in it right away. One is on order right now) and then dropped it off at the house when i was at work.

When I got home, I reinstalled it and the tractor did run for a little while and then died. I have not been able to run it every since. The one part that i notice was happening was that gas would come out of the air intake of the carb when i would choke it. I thought to myself... maybe the needle isn't seating properly or the float is rubbing the side and getting stuck. Upon review I didn't see any symptoms of that . I blew into the gas line part of the carb and air would blow through if the carb was right side up. If I turn it upside down then i couldn't blow through it. That was indicating to me that the needle was sealing. The bowl isnt overly full of gas. It appears to stop where the float pontoon line is.

After I ordered a new kit I started tearing the carb down ( I have experience with carbs just not this one but got my self educated lol). When reviewing the kit contents it also includes an idle jet. I noticed mine didnt have this installed in the threaded area by the needle and was wondering when my good friend cleaned it... did he failed to put this part back in?

This is where my head is spinning a bit..... When I looked at assembly literature online for this carb, it stated this model doesn't always use the idle jet. ??????????? Funny part is... the place i am ordering the full kit from has an online assembly manual as well. The kit includes that idle jet as i stated before. When looking at the manual it stated the same thing! but it is showing up in the expanded assembly view HAHA

Not even sure where the problem lies.

Maybe thats not my problem?

I had one guy tell me it could be a timing issue but i had this machine running last summer and fall so i dont think it is that?

I have had this carb apart 10+ times now. This tractor couldnt have died on a nice 78 degree day........ no it decided to conveniently do it with 3 feet of snow in the yard with sub zero temps and parked 300 feet from the garage...in which is not heated either haha I am glad i am still finding humor in all this. Fortunately i have nice neighbors that are blowing me out this year.


What do you guys think??


Thanks
Duane
Montevideo, Mn

I'm thinking there may be another problem, not necessarily the carb.

When the float sunk, it probably ran really rich before it completely died. If the fuel was not shut off, it could have even overflowed gas into the engine. Might want to check the oil level for overfull and look at the plugs for fouling. Look at the air cleaner, be sure it didn't get flooded with fuel.

While the plugs are out, check the spark at the plug end of the plug wires. It should have a 1/4" spark to ground at each plug wire. You may want to go with a new set of plugs, or a known good set especially if they are sooty black.

Now to the carburetor.

For an updraft to drip fuel following a failed choke assist start is normal. What you are seeing is unburned fuel draining back down out of the intake. It should stop in a few seconds. A truly flooding carb will begin dripping shortly after the fuel valve is turned on and will continue to drip indefinitely. It will also run bad and blubber black smoke.

As for the idle jet, you are asking about the jet itself, correct? Not the adjustment screw?

You should be able to look at the hole where the jet may have been. If it is not threaded, obviously there was never a jet there. If the threads are rusty, it was probably not there, if clean and shiny, then it was there. You could also call your friend and ask if he took one out.

But... Even if it is supposed to have the jet, that will not stop it from starting or running. It may idle too rich, but once the RPM is up, the idle circuit will have little to no effect on the running.

One other thing to look at, be sure the gasket is good where the idle circuit draws it's fuel up (the small hole beside the venturi). Also the sealing surface is important there. Sometimes the housing gets warped and the gasket doesn't seal properly.

If the idle screw makes a difference in idle quality, chances are it is right. More about that later.

Once the carb is back on, before connecting the fuel line, open the fuel valve and check the flow. It should have a good flow, not just a drip. This will also flush out any debris that may have gotten in the end of the line.

Once the line is connected, have a clean glass ready and open the fuel valve. Remove the drain plug from the bottom of the carb bowl, catch the fuel. It should have a full stream, it will slow as the bowl empties, but still have a good stream, not slow to a drip. Look at what was caught. It should be clean and clear. Murky will indicate excess water, chunks will be rust. If the fuel coming from the carb is dirty, the carb will also soon be fouled. Be sure the sediment bowl screen is clean and in place. Inline filters are sometimes used, but they can be restrictive, I don't recommend them.

I have a feeling if you get the ignition right, the carb will be close enough to at least run.

Once it's running, and up to temperature, it will need to be adjusted.

Adjust the idle mixture first. The engine needs to be at slow idle, 400-500 RPM. The mixture adjusts backward from modern carbs. Turning the idle screw in richens the mix, out leans it. What you are adjusting is air bleed, not fuel flow. Turn the screw out until the idle quality falters, then back in to best idle, then in slightly more, maybe a 1/16 turn.

If the screw has no effect, the idle speed may be too high, there is a vacuum leak, the idle circuit is clogged, or the gasket is not sealing the upper housing to the bowl.

Next the main jet adjustment. Turning the screw in leans the mix, out richens it. Start by turning the main screw in one turn. Try revving the engine suddenly. It should falter or die. If not, turn the screw further in, try again. Once it won't take throttle, start backing the screw out 1/4 turn at a time until the engine will take sudden full throttle without hesitation. A single puff of black smoke is the goal.

You may want to put off the final tuning until better weather, but if it is blowing black smoke under power, at least try leaning the main jet so it doesn't wash down the cylinders and foul the plugs.

Hope this helps, let us know how it goes...

Before you spend a lot more money, replace the spark plugs. They will be under $10-15. I found out that these newer plugs sometimes will not "dry" off after they are flooded. Two different good "modern car" Mechanics told me this just a week ago.

My GMC 1500 would not start the morning we hit -35F here. Battery weak. Installed new battery after trying to jump and charge the old battery. Engine still would not hit. Thought frozen fuel line. Built shelter all around the pickup and heated it up with a space heater. Still no go. Gave up and pulled it out of the way. Waited until we had a 35 degree day. Still no go. Called the local car guru. He told me that if I had the new platinum plugs they often will not fire after getting fuel soaked. Installed new spark plugs and started right up.

An ignition issue can often appear to be a fuel problem. I have had weak coils make a tractor only run with the choke out some.