1938 Unstyled B - hard starting in summer

acorn

Member
Hello! It seems that my B starts fairly easily during colder weather. Here is my routine:

1) Turn fuel on
2) Crank one full cycle on full choke, throttle almost all the way back (usually it will fire)
3) Put on half choke, increase throttle a little bit, crank some more. Usually starts in just a few cranks

However, this method isn't working since it's gotten hot. I have tried not choking at all, starting with half choke. Different throttle positions, etc... Sometimes it takes 20 or 30 cranks to get it going. Very tiring and sweaty job :)

The carb is a freshly rebuilt one. Adjusted properly (or at least it seemed to be). New plugs, wires, etc....

The only thing that I haven't messed with at all on this tractor is the timing. Does anyone have an opinion on changing the timing in winter vs summer? Not sure which direction to take here, but I'd sure like to be able to start it easier!

Thanks in advance!
 
Hello! It seems that my B starts fairly easily during colder weather. Here is my routine:

1) Turn fuel on
2) Crank one full cycle on full choke, throttle almost all the way back (usually it will fire)
3) Put on half choke, increase throttle a little bit, crank some more. Usually starts in just a few cranks

However, this method isn't working since it's gotten hot. I have tried not choking at all, starting with half choke. Different throttle positions, etc... Sometimes it takes 20 or 30 cranks to get it going. Very tiring and sweaty job :)

The carb is a freshly rebuilt one. Adjusted properly (or at least it seemed to be). New plugs, wires, etc....

The only thing that I haven't messed with at all on this tractor is the timing. Does anyone have an opinion on changing the timing in winter vs summer? Not sure which direction to take here, but I'd sure like to be able to start it easier!

Thanks in advance!
Sounds like weak spark and magneto needs attention, anything from points and condenser to new coil which is rarely included in a "rebuilt" one.
 
Shouldn’t have to change the timing I wonder if your throttle shaft might be loose in the carb letting air in since it doesn’t seem like it’s flooding after what it an incredible amount of cranking. When running it idles well? What I think the giveaway is at 30 cranks with choke on especially you should be flooded out to the point you have to pull plugs can’t turn the cylinder easiest thing to do would be go away for lunch and a rest after throwing that thing over. You aren’t getting fuel in there.

So on mine I did just do a throttle shaft and it helped immensely you could push on it to get it to wiggle and could easily tell it wasn’t tight.

Above 50 degrees if everything is correct it shouldn’t need much choke at least the 38 and 36 I’ve had both do not need it.

The procedure I had come up with was before replacing it was this.

Roll flywheel back half a turn with throttle at half. Do not go past impulse this will fill one cylinder with fuel.

Roll forward till it pops it should pop second crank as that’s the one you filled.

Close throttle while it’s on the momentum of the pop to shut the air supply a bit and it will pop again and you can open it up.

Plugs fresh would be the other question. Good luck!
 
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Sounds like weak spark and magneto needs attention, anything from points and condenser to new coil which is rarely included in a "rebuilt" one.
Hmmmm... New points and condenser - but old coil.... I think. I'll have to look.. thank you!
 
Shouldn’t have to change the timing I wonder if your throttle shaft might be loose in the carb letting air in since it doesn’t seem like it’s flooding after what it an incredible amount of cranking. When running it idles well?

So on mine I did just do a throttle shaft and it helped immensely you could push on it to get it to wiggle and could easily tell it wasn’t tight.

Above 50 degrees if everything is correct it shouldn’t need much choke at least the 38 and 36 I’ve had both do not need it.

The procedure I had come up with was before replacing it was this.

Roll flywheel back half a turn with throttle at half. Do not go past impulse this will fill one cylinder with fuel.

Roll forward till it pops it should pop second crank as that’s the one you filled.

Close throttle while it’s on the momentum of the pop to shut the air supply a bit and it will pop again and you can open it up.

Plugs fresh would be the other question. Good luck!
Thanks for the detailed reply! Throttle shaft is good. I'll pull the plugs, but they're pretty new. Thanks again!
 
I've heard that the newer fuel can make these hard to start. It is too 'hot' with the ethanol (explodes to fast). Haven't tried it, but heard you can add kerosene to make it closer to what the gas was like when the tractor was built.
 
Shouldn’t have to change the timing I wonder if your throttle shaft might be loose in the carb letting air in since it doesn’t seem like it’s flooding after what it an incredible amount of cranking. When running it idles well? What I think the giveaway is at 30 cranks with choke on especially you should be flooded out to the point you have to pull plugs can’t turn the cylinder easiest thing to do would be go away for lunch and a rest after throwing that thing over. You aren’t getting fuel in there.

So on mine I did just do a throttle shaft and it helped immensely you could push on it to get it to wiggle and could easily tell it wasn’t tight.

Above 50 degrees if everything is correct it shouldn’t need much choke at least the 38 and 36 I’ve had both do not need it.

The procedure I had come up with was before replacing it was this.

Roll flywheel back half a turn with throttle at half. Do not go past impulse this will fill one cylinder with fuel.

Roll forward till it pops it should pop second crank as that’s the one you filled.

Close throttle while it’s on the momentum of the pop to shut the air supply a bit and it will pop again and you can open it up.

Plugs fresh would be the other question. Good luck!
Oh, by the way - yes, once it's running, it runs like a top. Idles fine, good power, etc..
 
I've heard that the newer fuel can make these hard to start. It is too 'hot' with the ethanol (explodes to fast). Haven't tried it, but heard you can add kerosene to make it closer to what the gas was like when the tractor was built.
Interesting! Also, I have been running ONLY ethanol-free gas in it. I do know the tractor originally only started on gas, then you switched over to "inexpensive fuel oil" (kerosene) while you were working. I've been wondering about plumbing that system back up to try it out sometime.
 
I suppose carb gasket leak on the manifold side would do it as well as a carb that would need cleaned. A quick test to see if it’s a fuel problem is give it a sniff of ether as well.

So on your alternative fuels subject e85 will act much like kerosene mid summer it’s great below 50 it will struggle so I have often thought about re-plumbing that small tank for gasoline as well but I honestly don’t mow much below 50. It does make a sweet smelling exhaust though and it does start below 50 just more difficult
 
I suppose carb gasket leak on the manifold side would do it as well as a carb that would need cleaned. A quick test to see if it’s a fuel problem is give it a sniff of ether as well.

So on your alternative fuels subject e85 will act much like kerosene mid summer it’s great below 50 it will struggle so I have often thought about re-plumbing that small tank for gasoline as well but I honestly don’t mow much below 50. It does make a sweet smelling exhaust though and it does start below 50 just more difficult
Thanks again. Carb to manifold gasket is new, as is the carb, practically. It hasn't sat for more than a week without at least running it up to temp since December, which is when we initially got it broke loose and running again. I may try ether, but i'm leaning more towards a weak spark issue for some reason at this point.
 
took an unscheduled break from work and went out to the B. First I turned the gas on and tried to start it with no choke. No pop, no nothing. Next I pulled the plugs. they appear to be fine. I used an in-line fire tester, and I don't see any spark, however. I also just discovered a leak at the fuel shut off at the sediment bowl, which runs down onto the left plug. So I did NOT pull the plug out and test for spark that way!

Anyways, from what I seem to see now, I don't have any spark. I will open up the magneto next, and check the (new) points. Maybe they came loose or something. Maybe the warmer weather is just a coincidence.
 
I would check the point gap, .015. Then run some emery cloth through the points. Then wipe clean with a clean paper business card. If not, you may need a new coil to get your blue-hot spark? You are doing right by using E-91, ethanol free gas. Everything starts and runs better on this gas. And this gas has a long shelf life. You talked about trying kerosene? Do it, it will work. I had a 1937 B that I used diesel fuel, starting on gas. The only thing you need to do is close the shutters, and get the coolant temp up to 200 degrees when running gas. Then turn the fuel over to diesel and go to work, keeping temp hot. Works good. Only problem is when you stop and idle a while, it will smokes like crazy. Fun tractor to work with.
 
If you need help on the mag, I do them as a hobby. I have the proper testers that takes the guess work out. Also have the magnet charger to charge the magnet for a good hot spark. Weak magnet = weak spark.
 
If you need help on the mag, I do them as a hobby. I have the proper testers that takes the guess work out. Also have the magnet charger to charge the magnet for a good hot spark. Weak magnet = weak spark.
Thank you! Might take you up on that. Points look fine, and they, and the condenser both, are new. I spun the tractor over using the clutch drum, since the mag is on that side, back and forth a few times, with the mag cover off. Only once did i see a spark at the points, when it snapped. Mostly, I didn't see any spark at the points.
 
I would check the point gap, .015. Then run some emery cloth through the points. Then wipe clean with a clean paper business card. If not, you may need a new coil to get your blue-hot spark? You are doing right by using E-91, ethanol free gas. Everything starts and runs better on this gas. And this gas has a long shelf life. You talked about trying kerosene? Do it, it will work. I had a 1937 B that I used diesel fuel, starting on gas. The only thing you need to do is close the shutters, and get the coolant temp up to 200 degrees when running gas. Then turn the fuel over to diesel and go to work, keeping temp hot. Works good. Only problem is when you stop and idle a while, it will smokes like crazy. Fun tractor to work with.
Thanks, point gap is fine and points are clean - but still no spark at the points, most of the time. Thinking i'm gonna have to get the coil checked or replaced, maybe....
 
Points look fine? Clean the points by pulling through a piece of emery paper a few times. Then clean with a new paper business card. Even though they are new. There can be a film on the new points face.
 
Hello! It seems that my B starts fairly easily during colder weather. Here is my routine:

1) Turn fuel on
2) Crank one full cycle on full choke, throttle almost all the way back (usually it will fire)
3) Put on half choke, increase throttle a little bit, crank some more. Usually starts in just a few cranks

However, this method isn't working since it's gotten hot. I have tried not choking at all, starting with half choke. Different throttle positions, etc... Sometimes it takes 20 or 30 cranks to get it going. Very tiring and sweaty job :)

The carb is a freshly rebuilt one. Adjusted properly (or at least it seemed to be). New plugs, wires, etc....

The only thing that I haven't messed with at all on this tractor is the timing. Does anyone have an opinion on changing the timing in winter vs summer? Not sure which direction to take here, but I'd sure like to be able to start it easier!

Thanks in advance!
The problem has been resolved and I want to thank everyone, especially @teddy52food , who rebuilt my Wico C mag. There were a few issues with it, and the points were actually mis-aligned. The tractor starts now with just a couple of cranks, after priming :cool::thankyou:
 

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