MTFCA Forum

Am hoping there are some Fordson folks on here - the antique tractor forums don't seem to have many active Fordson enthusiasts. I recently acquired a 1923 F. Starts (when it wants to) on mag without battery assistance - not easily, but eventually. Has a lot of trouble starting when it's hot (very difficult to get running again immediately after being shut down). It has the Kingston M-D setup. Yesterday, after running for about 35 minutes, I shut it down and began getting raw gas out of both ends of the air supply pipe between the air washer and mixer. A lot of raw gas. Also, the air washer was filled with white smoke and smelled of gasoline. Any ideas on what is causing this and what to check to fix? Thank you in advance for any assistance (and yes, I have Model Ts as well).

Jim,
Fordson's can be a bit troublesome to start. My view is it has to do with the design of the vaporizer, the fuel leaves the tank goes down to the level of the float bowl, and then has to drawn up through the vaporizer plates to the air intake and then back down to the intake manifold. If the tractor has great compression then there is plenty of vacuum to draw the fuel. If not then they can be rough to get started.
From your description I bet the needle and seat in the float bowl is not sealing, that is the bowl just below the rectangular heat plate on the MD. It is where the fuel line attaches. That is allowing raw fuel to go up into the heat plate where it is heating and coming out the air pipe and causing the white smoke in the air washer you described,
Hope this helps,
Kevin

Kevin,

I greatly appreciate the reply. But there would have to be flow between the needle and the seat or fuel would never make it up to vaporizer plates and tractor would never start. They couldn't really be sealed.

I have a 23 Fordson also but with Holley 280 vaporizer. The float bowl is even further down. There is a big air tube which runs to the top of the vaporizer and a second smaller air tube which passes thru the float bowl were the mixing needle is. All the airways are sealed. The top of the vaporizer also has a priming cup. It too is difficult to start and seems to require a lot of fuel. I think they may have a tendency to vaporlock which might cause your fuel to keep flowing. Are you running with coils and the ford mag? I have an aftermarket FM impulse mag which does make it a little easier. Also make sure the vent hole in your gas cap is not plugged. Do you have any pictures?

By the way what are you using for motor oil and rear end lube?

Joe,
The small reservoir at the bottom of the vaporizer plate has a needle and seat that is controlled by a small rectangular float. That bowl fills with fuel and then is drawn in small amounts up the through the vaporizer plate to the mixer. If that float and needle and seat cant control the fuel it is a simple matter that it will gravity feed until your tank is empty.
It has been a while since I have owned a Fordson, but I have had tractors with both the 295 Holley and the Kingston MD. Both work in similar fashion and my understanding are a much better set up than the 280.
I have tons of literature, I will go through some and see what I can dig up,
Kevin

My needle is right next to the bowl float assembly. It is just to the right of the lower part of the red starting tank. An air intake comes out of the main air intake and mixes at the needle and runs to the low part of the vaporizer which is a coil through the exhaust manifold. L shaped piping. There is a flap which opens in the manifold for faster heat and also colder days when running kerosene. Start on gas, warm up and run on kerosene. Gas is cheaper but you have to watch the heat. I’m running gas on both tanks right now.

On the subject of Fordsons, does anyone know of a source for valves? A friend is working on a 20 model and would like to replace the badly worn valves. Thanks for any help.

Joe,
I have attached a couple of scans. When you mentioned your vaporizer was a coil, it got me thinking. Kingston MD's have a large rectangular block that has a maze cast in it for the hotplate. Earlier Holly's have the coil.
Again hope these help,
Kevin

PS John as far as valves, try the Fordson House in Michigan

Joe, Kevin:

I appreciate the responses. Am running only on gas and from the main tank. The starter tank on mine is integrated in the main tank (not bolted to air washer). On mine, to start it, the mixture needle must be opened at least 4 full turns off full seat. Once running, I can lean the mixture a little, but not much or it will stall out. Kevin, are you saying I need to lean it out more to prevent the raw gas issue?

Joe, I run 30 wt non-detergent in the engine (like my Ts). Have no idea what is in rear end right now, but suspect 600.

Here is a picture from when I picked it up. Will be ordering a new radiator from Fordson House.

Kevin, Thanks.

23Fordson,

Congrats on your purchase. 4 turns out on the mixture is a lot. It should start and run at about 1 1/2 turns out - choked or primed if cold. You might check your vaporizer system for air leaks. If any of the intake system isn't sealed, it's hard for the system to draw vapor since it's sucking air. Thus, you have to turn the mixture up to compensate. You might also check your ignition timing, as it sounds like it chuffed out the intake. There were several different timer rods used through the years, and they have different lengths. A mismatch of linkages can lead to an inability to get the timing right. Also, keep in mind that an F timer is rotationally indexed differently than a T. I also suggest that you get it running well without water in the air bath first. Use a block of wood to prop up the float, as the air bath float blocks off the air inlet if the water gets too low (or is drained). Having water in the air bath adds a whole new level of adjustment since it takes more effort to suck the air through the water. Also, happy to have you here of course, but you might try the steel wheel section on the Smokstak forum. https://www.smokstak.com/forum/forums/a ... actors.22/.

Kevin, plate 16 diagram is my vaporizer setup. Joe, I have to start mine about 4 times out on the needle and then can lean it. Maybe a valve issue. I can not run it with out water in the air bath because it seems to need that back pressure. I put packing foam in it to hold the float open and could only run it partly choked. Does yours have a priming cup on top of your vaporizer? I have a 36 Fordson N with a downdraft vaporizer that starts easier.

Nikolaus,

Four turns seemed a lot to me as well (being accustomed to Ts and As at 1.5 turns). Will check vaporizer for leaks. Timer rod looks original to tractor. Can you clarify what you mean by "the F timer is rotationally indexed differently than a T?" It has a New Day flapper style timer, so I know that was changed out from original at some point.

Nikolaus - would you happen to have the length difference in timer rods (might as well check that too - even though it looks original)? Fordson House lists 2 styles (17-27 and28-38) - but gives no information on lengths.

23Fordson,

The rod hookup on a T is straight up, and the rod hookup is 90 deg off from this on an F (at 9 o'clock if standing in front of the tractor). Some aftermarket timers have the wire color labeled, which is for a T, and on an F, the timer is rotated by 90 deg. You just need to be aware of that when using the timer on an F so that you don't end up with all the ignition off by a stroke. You can make the colors match on the timer; you just need to be aware of the relationship between that, the coil box, and the cylinders. I don't know the rod lengths, but suspect they'd differ by an inch or a little more. One version has the timer control rod along the top edge of the head, and one version has that rod dropped alongside the head, hence the difference in length of the timer hookup rod. I'd worry less about that and more about actually timing the ignition to the piston the same way you would fine tune a T by bending the timer hookup rod. With the vaporizer system, you need a good tight, sealed intake system, and you need decent compression (vacuum on the intake stroke) to draw vapor in. A Holly 295 has a strangler valve in the intake to increase vacuum on the vaporizer. I assume other intakes may, as well. This is a free-hanging flap (butterfly) in the intake tube that self-closes at idle and opens up as the engine draws more air. You might check to see if your intake design has that, it's present, and it's not stuck open. Another thing to help get you going is to unhook the magneto and get it going on a battery first (as with a T, don't put battery voltage to the mag). That would allow you to know that you have power, as well as do a magneto output test while the tractor is running on battery. Just like many Ts, many Fs will run on mag but not start well on mag.

Also, yes, 30 weight is fine. Rear end oil needs to be yellow metal compatible due to the worm wheel. Amazon has 5 gallon buckets of Mobil 600W Super Cylinder Oil for about $140 shipped. The F will take 3-3 1/2 gallons, and you'll have a supply left over for your T or most any other old car diff. You can use a cheaper and/or thinner oil so long as it is yellow metal compatible and you don't mind a little more howl.

Appreciate the reply(s) Nikolaus. You've given me some great things to check. Thank you!

Ya’ll I cheated ....I tried following the up and down movement of the raw gas as it turned into an air/fuel mixture and found that sheet metal ‘coil’ was toast so I turned to the old standby NH carb. Makes starting and running much simpler....Question: How do I keep the 2 bolts fastening the bottom of the radiator from leaking??..they extend up into the lower tank coolant.

George's photo shows the version of control rod that is dropped down along the head. The higher version has that rod up even with the head bolt heads (no drop). I'm not familiar with the radiator bolt leak problem, but I know what you mean. Perhaps some silicone smeared on the bolt threads?

Mine is even with the head bolts.

Interesting thing is the coils don't buzz - ever. Have started it probably a dozen times and no buzz. Previous owner said they never buzzed for him either.

George, I like the NH carburetor setup. It makes it down draft. Is it prone to flooding? Are you using the water bath aircleaner? Joe, your coils must buzz if it is running, probably can’t hear them over the engine noise. A battery is the only thing that makes them buzz in a T before starting.

Howdy Joe,
There’s no problem using an NH carb on a Fordson. I have one on my ‘19 ladder side 6 spoke rear wheel too. Don’t use the water bath air cleaner either. Just don’t plow in a dust storm.