It's a Model B, not a Model T, but it has four cylinders and a magneto. My mowing tractor runs smoothly enough at full throttle, as you see at the start and end of the video, but listen to what it does at a slower speed, and see what happens when I try to run it at idle speed. Any ideas on what's the problem?
Usually when an engine is hunting up and down on the governor, it's carby adjustment, reset the mixture screw.
How much play in the throddle shaft in the carburetor? If the shaft has to much play, the holes in the carb are to loose from wear, it will suck to much air around the shaft and mess up the gas mixture. You may have to rebuse the holes. A shaft that is to loose will not allow it to idle worth a darn.
OK, when I get some daylight I'll try carb adjustment and check the throttle shaft.
Sounds like bad leak in intake manifold or intake gasket.
Spray the gasket edges with carb cleaner with engine running.
i get that when the spring tension in the governor is too high. But it's not really a great fun thing to reset from memory as i often made it worse.
Probably just wear and tear..
I agree with Frank, the video seems to indicate a fuel delivery issue. It may be able to be fixed with an adjustment, there may be gunk in the carb effecting the flow of fuel. Try spraying a little ether in the carb (or if manual choke, close it a bit) while its running if it smooth's out, that will be the indication of lack of fuel (you can also try putting your hand over the air inlet of the carb to choke it that way too).
If it is a lack of fuel, may be some gunk in the idle circuit of the carb (which I assume it has a high and low circuits in it.)
By the way, it may not be a T, but it is the right color tractor in my opinion.
(Message edited by Chad_Marchees on April 23, 2016)
By some chance are you running ethanol fuel, Ethanol fuel is very hard on old carbs without some kind of stabilizer, I would check the ports in the carb for corrosion.
I'd start with re-adjusting the idle mixture
Steve in my highly educated and practical opinion----
Your tractor is broke!
Paint it green with yellow wheels and the problem will go away.
Yup,It's the ethanol fuel sure as heck! Yesterday i got the power washer out first time since late October and the darn thing started on the second pull!!Those tractors had trouble with the coil in the mag overheating and the governor might hunt around trying to make the speed you set?? PS,There was a reason everyone dropped the mags about the same time and went to a distrubitor and never looked back!
I say try some fresh gas as well.
The reason they dropped the mags and went to a distributor is because mags are so expensive.
Usually shortening the link between the carb and governor will fix that.
After 75 years of use a little wear here and there adds up.
Governors don't like free play anywhere.
I can't watch videos due to dial up,but if I am dealing with a "hunting" engine I usually spray something like wd-40 around all gasket surfaces and check for air leaks.
Throttle shaft wear is the leading cause of that on old stuff.
Sometimes the old brass floats will collapse or start filling up with gas and as that happens the engine floods at idle but will burn the fuel under load.It has to get really bad to cause trouble under load.
BTW mahlon, He would need to paint it Flambeau red and Desert Sunset to really fix it, that green causes it to cost more GREEN.And we all know Steve does not like parting with GREEN if he does not have to.
And to save googling,those are J I Case colors.
I think it needs a new fuel tank.
Just for grins & giggles, and a relatively easy and fast attempt at a fix (so you can work on the roof and siding again) - try some of that often spoken of MMO. (an ounce or two to a gallon of that ethanol).
I couldn't think of anything to add to your thread so I X'd out of the tab and THEN Jerry's joke grenade about the fuel tank went off! Hehehe!
Have you had a chance to get that little Almer running sweet?
It's not a Ford, I would start there.
I like the paint it green with yellow wheels. Could be a air leak somewhere?
Any update you care to share?
Had what I think was the same issue with my Allis B. (I can't watch your video as I'm at work) There is supposed to be a "stabilizer spring" that goes from the throttle rod between the carb and gov to the engine block. Its job is to prevent the governor see-saw action. Had a 42' B, ex US Army tractor. It was the best dang tractor I've ever owned. It would put my neighbors JD H to shame every time.
Found the part at-http://www.yesterdaystractors.com/Allis-Chalmers-B_Governor-Rod-Linkage-Spring_7 0212321.html
Hope this helps.
Shucks, Steve, when you said it was a Model B, I thought that you meant a doodlebug tractor with a Model B Ford engine. Boy, am I depressed.
The other thing that I can think of, is it is not painted Ford (Fordson) gray. Ha.
The farmer who sharecrops my place uses some green equipment, but when my family was farming it the only tractors on the place were Allis (Model C), Farmall (F-30), and Ferguson (don't remember the model) after they retired the nags. I learned to drive on the C when I was ten, so when I bought a mowing tractor several years ago it was an Allis.
I've been busy with other chores, so haven't tried all the suggestions above. But I did spray ether around the intake manifold and carb with the engine running. That had no effect. I'll try some of the other things and see if they help.
There should be a spring that hooks to your throttle shaft rod behind the carb and forward to a manifold bolt This keeps the governor from hunting at an idle.
My guess is the idle jet/circuit is plugged. See this a lot on old British motorcycles and old gas varnish. Keep in mind, just a guess.
Wild guess. Does the magneto have a condenser? If so, they can cause all kinds of problems. If not, never mind. Dave
I once had a Model A doodle bug that lost the ground on the condenser and it gave me fit's! I'm sure the mag has a condenser but i do not remember if the Fairbanks Morse mag runs at double speed with a gear for the points and a reduction like a IH or not? I also started very early on a C Allis and then our F-20. Later in life i had a WD and a WD-45 then a 190 XT and my last Allis was a HD-21 with a 12-71 Detroit!!!!!!!!!!!! Bud in Wheeler,Mi.