Allis WD Running Rough Update With Vid

Ken Christopherson

Well-known Member
Ok everyone.. After getting out to see the tractor that I posted earlier about (originally thought it was a WD45, but it is in fact a WD).. Here are the things I went over:

- Adjusted the valves to .014"
- Checked inside the tank: Clean
- Checked fuel flow from tank to bowl, bowl through line, and then cracked the drain on the carb. All is good
- Adjusted idle mixture screw to 1 1/2 turns out. Set load screw to approximately 1 1/2 turns out (it was nearly 4 turns out)
- Checked the plugs (running Autolite 295).. All but #4 were pretty fouled. Cleaned them all as best I could (he didn't have new plugs). Set them to .030"
- Checked the points over. Some cloudy/discoloration on them. Polished them up, set them at .020"
- Noticed that the valve cover gasket was leaking considerably near the front
- Compression test conducted - wide open throttle, no choke. All cylinders had approximately 90-95 PSI.
- Started tractor up. Warmed up. Seemed to run fairly well. Adjusted Load needle to approximately 1 3/4 turns out. Idle was at about the same. Adjusted idle speed up some (was set too low)
- Shut tractor down to fuel up (let set for about 10 minutes). Started back up, tractor seems to 'hunt' throughout midrange rpm's. Also has a decent amount of popping/backfiring through carburetor. Tried to make more carb adjustments without much success. Pulled choke out to about 1/2-3/4 choke and seemed to alleviate symptoms slightly.
- Also, checked connections near manifold and carburetor with both propane and carburetor cleaner to test for leaks. No change in RPM.
- I also noticed, the exhaust port of the cylinder head at #1 cylinder seems to glow whenever there is a pop/backfire. Almost as though the casting is extremely thin at this point.

It is a 12 volt system, distributor with 6 volt coil and ballast resistor & alternator. Also, he replaced the ignition switch with a key switch. (Not sure if this has any bearing on the problems). To shut the tractor off, you must turn off the fuel. You can turn key switch off, battery disconnected and it will still run.

I have enclosed a video of the tractor running. It seems the governor/carb hunting only happens mid-range on RPM's. I get some popping back through nearly the entire throttle range. I have removed the carburetor to do a complete overhaul on it (Marvel Schebler TSX159).. Also will be replacing the valve cover gasket. At this point (other than new spark plugs), I am unsure what to check. Could the governor assembly be worn/need adjustment?

Like I say, I am new to Allis, so any help is appreciated! (Video should be ready about 6:30 PM Central Time
Allis WD Troubleshooting
 
I worked on one that had been converted from a mag to distributor with a Delco adapter. The drive was so wore out it had the timing off all the time. Take the cap off the distributor and see how much play is in the rotor, this one could be up to a post off on the cap. Just something to check out.
 
You never can rely on the amount of turns to properly adjust a carburetor.
try this: With the tractor at idle adjusting the idle jet along with the stop screw on the back to a slow idle. )I always try to as slow of an idle I can get and still open it up without hesitating) When you get idle set to where you like it open the throttle up to its fastest speed. Adjust the power jet until you get the fastest RPM. Turn the adjustment in and out slightly until you are sure you have it running as fast as it will run. Then turn the needle in until you notice it to slightly slow in RPM. (slightly) This will be as good as you will get it unless your on a dyno. Counting the turns is for getting it to run not to tune it.
 
I forgot to add that the stop screw on the back sets the idle RPM. The idle/air mixture screw is adjusted to make the engine run smooth at the stop screw setting.
The idle/air mixture screw adjust the amount of air with the fuel for idle.
The power jet adjusting screw adjusts the amount of fuel mixed with the air being pulled thru the engine after the engine is running.
 
A (total) rebuild and it (might have some passages plugged?) After listening to the video it most likely is some stuff floating around. I would disassemble then boil it in soap water. then run small drill bits and wires into and thru all passages using my fingers not a power drill. Run a tap in the inlet to clean the threads. I use a 1/2 cup of liquid laundry soap in my pot I boil carburetors in. This softens (most) of the crud. The crud that has car carboned up needs scraped or glass beaded.

008-vi.jpg
 
Dick L,

This is essentially what I did. I started with both screws set at 1 1/2 turns out, started the tractor. Ran pretty good. Brought it down to an idle, and the idle speed screw was set far too low. Opened it up some and then dialed away the missing the the idle adjustment screw. Then, brought tractor to wide open. Turned load screw in until tractor RPM dropped, and opened it up about a half turn from there. To check for hesitation, I brought the tractor down to idle then cracked it to wide open. Tractor does not cut out. To me that is set pretty good.

The issues didn't start until we turned the tractor off, refilled with fuel, and started it back up again. Sounds to me like one of two things: running the tractor out of fuel moved some crud in the carb around (or), the fuel he added was old fuel.

Either way, after opening the carb up there was a LOT of crud inside so I am going to soak for about a week in my Chem Dip, and then boil in hot soap water as stated above. I'll blow everything out with compressed air and wire out the passages.

Also, from what I have read.. 90-95 PSI on the cylinders is borderline for a rebuild. He may be looking at that sometime soon as well.
 
I did double check this as well. I did a fair amount of research prior to heading over there (it is an hour drive for me). Firing order should be 1-2-4-3 if I recall. Everything was set up correctly with that. Plug wires were in good shape. All contacts on plug wires were clean. I cleaned the plugs as best I could (he did not have new plugs for it). I am going to recommend he gets some NGK plugs for it though when I bring the carb back to reinstall.
 
I did also clean/polish the the points and reset them to .020". I did check the play in the rotor, and it seems pretty good. Maybe 1/16" or so of play when wiggling back and forth.
 
Although not necessarily a serious issue, the exhaust manifold leak is what caught my attention. That's an original WD manifold on there, and that's pretty rare! Most have been replaced/updated long ago. That style hasn't been supplied for a long long time. I suppose new manifold gaskets could heal it for a while, but I imagine once removed, that manifold isn't worth messing with.

Since you are working on the carb, it wouldn't hurt to check the carb to governor register. Like the manifold leak, this is not something specific to this engine, but quite generic. The governor and carb want to be wide open at the same time, but you don't want the throttle shaft jammed hard against the stop. Different companies have different ways of describing this("lengthen till pin goes in, then turn one turn") etc. In this case, the only adjustment is bending the linkage.
 
I wouldn't say it was border line if it has been setting for a time. Re read the power jet setting I posted. You really need to remove the power jet and clean behind it with something as well under the discharge tube in the neck. I know it can't be real bad but that is an area when setting that the gas evaporates and gets sticky.
 
Tractor was being used pretty regularly up until a couple months ago when it started backfiring so bad it was hard to run at all. I've got the carb off and back at my place. It is soaking in my gallon of Chem Dip, and will get boiled out afterwards. I'll also wire out all of the holes/use small drill bits to clear out passages. Full rebuild kit coming for the carb as well. Going to have him get new plugs for it to also help with any issues of fouling. We'll see what happens from there.
 
I did take a propane torch and flood the area with propane to see if I got any changes in RPM. Nothing. Also tried using carburetor cleaner around the manifold connections with the same result. (No changes in RPM). I'm thinking the manifold still may be ok.

The governor to carb rod does have a little play in the connections, but it's not too bad. I'll take a look at it more when I get the carb finished up and reinstalled. We will do a test run to see where we are at.
 
Probably the intake portion is OK. But letting the exhaust pop can over time erode the face of the head. It may be just my observation, but I hate hearing that pop enough that it's difficult to hear whatever else is going on.

I wouldn't be concerned about the slop in the gov/carb linkage, but would definitely check the "register".

AC used to employ, as required, a little spring from that link to a manifold bolt, to attenuate the governor, which can be over active.
 
Nothing wrong with NGK plugs, but my favorite plug in all of my mag fired A-Cs is the Autolite 295. For battery ignitions (distributors) I use Autolite 303 plugs, but have used 295s on these as well with great results.
 

For Manifold Bolts, I used Hardened replacement bolts with a Hard Steel washer under each one..Silcone gasket maker on the threads..

At least 2 of those studs should still be OK..

Those metal cups are important... They allow the Manifold to move as it heats and cools..

I still use Hi-Temp Silicone on every asbestos gasket and that holds the gasket and cup together in place, while I slip the manifold back in place..

A little Graphite spray around or on the cup surface that meets the head may be a good idea..

Bolt it evenly and fairly tight..not loose but not stretching the bolts tight..!

You WILL find that the AC is pretty "Cold Blooded" and needs a fair amount of chock after starting ( Cold)..
 

Carb settings are arbitrary beyond the initial settings..

A lot depends on just what the Job for it is...

A nice running setting for normal/Light loads is set it to a nice NO Smoke setting ( Lean) as it will take and run with a good transition to Throttle-up..

For really HARD "All DaY ) work turn the Power screw OUT another full 1/4 Turn.. you will get "Best Power" and the valves won't burn..
 
Regarding the no-stop problem, you are getting back-feed from the alternator. You either need a diode between the coil and the alternator, or adjust the idle speed so low that the alternator output ceases, and/or the mixture is cut off. You will have to manually control the idle with the throttle lever.
 
The interesting part is it worked properly prior to replacing the ignition switch. Replaced the switch and now it backfeeds from the alternator..
 
I should point out that I was referring to a multiple-wire alt. system as opposed to one-wire. In the multi-wire, the line going to the coil is tapped so one leg of the regulator is "hot w/ignition on". The other leg may have a short pigtail going to the bat post for "hot at all times". I can't really make any recommendations with out seeing how you have it wired, as changing the switch should not make it operate differently. I know you already have a lot on your plate, but I would consider , after you get this thing running right, to round up all the necessary components and go back to six volt. 12 volt WD-45s are nothing but trouble. I have a client with a 12volt WD-45 used at a stable, and change the starter every 9 months to a year. Always breaking the drive springs, but now ready to knock teeth off the ring gear. Had to install special long gear to reach in far enough to catch the ground -off teeth of the ring gear. The end Is near for this tractor. If you can get your tractor running right, you have enough wherewithal to properly maintain a 6 volt system. Thank you for allowing rant.
 

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