rebuilding the hand crank-F20

SDE · Jul 27, 2015

The shaft that extends out of the bolster is 7/8. It was slightly bent and is worn. My hand crank has a 3/4 inch opening. To use that crank, I made an adapter that fit onto the shaft. The bolster opening is very worn. One inch on the front and 1.2 on the back. I decided to replace that shaft with a 15/16 inch shaft, that I have turned the end down to 3/4, so that I could use the hand crank without the adapted.

If I hand cranked this tractor, as the expert said it should be cranked, I could crank all day and it would not start. If I started at the bottom and went over the top to the 2 o'clock position, it would start on either the first or second attempt.

I think someone has replaced this shaft in the past. (bad looking weld job). Here is my question. Could they have welded the shaft in place with the drive pin in the wrong location, in relation to the bracket on the other end?
Could this be why I need to go to 2 o'clock to get it started? Also I have not welded the new shaft together yet, and if it makes a difference, I would like to know now, instead of later.
Thank you
SDE

AlanA · Jul 27, 2015

(quoted from post at 03:40:20 07/28/15) The shaft that extends out of the bolster is 7/8. It was slightly bent and is worn. My hand crank has a 3/4 inch opening. To use that crank, I made an adapter that fit onto the shaft. The bolster opening is very worn. One inch on the front and 1.2 on the back. I decided to replace that shaft with a 15/16 inch shaft, that I have turned the end down to 3/4, so that I could use the hand crank without the adapted.

If I hand cranked this tractor, as the expert said it should be cranked, I could crank all day and it would not start. If I started at the bottom and went over the top to the 2 o'clock position, it would start on either the first or second attempt.

I think someone has replaced this shaft in the past. (bad looking weld job). Here is my question. Could they have welded the shaft in place with the drive pin in the wrong location, in relation to the bracket on the other end?
Could this be why I need to go to 2 o'clock to get it started? Also I have not welded the new shaft together yet, and if it makes a difference, I would like to know now, instead of later.
Thank you
SDE

Actually, my '39 H has the same issue, to a lesser degree. I don't know whether it is because I am weak, or short, or both. I could never get enough momentum on the upstroke to let it coast past TDC. I'm right-handed, so I stand to the left of the crank facing the tractor, as you should, and lift it gently. As it passes 11:00 or so I step back away from the tractor and keep my hand pulling on the crank, making sure no part of my body enters the arc the crank can reach, and wind up 12:30-1:00. I pull 1 time with the choke on full, and magneto grounded, then the 2nd pull at 1/3 to 1/2 choke and it will start every single time
. Doing it that way takes so little effort I could do it 3 weeks after open heart surgery. I was limited to 5 lbs of lift, and that is all I used.

Andy Martin · Jul 27, 2015

I think TDC should be about 10 o'clock. So long as you are in a position where if the engine fires before TDC and runs a revolution in reverse, jerking the crank out of your hand, you won't get hurt, the true requirements for hand cranking are met. The way AlanA is starting it, with the mag off, you are drawing rich gas into the cylinder which will go to TDC on the next crank.

AlanA · Jul 28, 2015

Forgot to mention on mine, the mag trips at 12:00 and 6:00. I have it time to fire 1-2 degrees ATDC. It actually has more compression now than it did right after my surgery last year. I worked it about 3 hours at WOT fully loaded with a 6' mower and compression was NOTICABLY better afterwards. No further improvements. I guess the rings just needed to be de-carboned. 8)

SDE · Jul 28, 2015

So I should rotate the engine to TDC and then position the hand crank to about the 10 o'clock position and then weld the shaft to the bracket.
Thank you
SDE

F-Dean · Jul 28, 2015

Sounds like you have a crank for a H or M. It may be easier to get the correct F-20 crank.

F-Dean · Jul 28, 2015

To avoid "Cranking it all day," use the "Twisted Belt" method of starting it.

Use another tractor and a flat belt to turn the engine while you make adjustments. Align the 2 belt pulleys and put a flat belt with 1 twist to turn the F-20 engine. This is easier than cranking to get it running.

350 dave · Jul 28, 2015

"If I hand cranked this tractor, as the expert said it should be cranked, I could crank all day and it would not start. If I started at the bottom and went over the top to the 2 o'clock position, it would start on either the first or second attempt. "

Not sure what the expert said, but.... like Alan A said... my 43 M engages at about 7-8:00 from the front looking backwards and lets go somewhere around 1:00, I pull full choke 3/4 throttle, walk around the tractor twice counter clockwise and it will start on the 2nd or 3rd pull every time.
Sounds like you got a truly good and and timing is right, so weld the thing so it works in a safe manner for you.
On some I have seen have a roll pin installed.
I think you are right about the previous weld being wrong. Somebody was in a hurry and did not think it out.

Farmallb · Jul 29, 2015

I am 68yrs old. I started farming with a F-20. Have had 4 of them that I can think of and 2 30s, along with my granddads 34 CC Case. I NEVER started from the bottom and came up. I always started at around the 1 or 2 00 position, standing to the left and hauled down on the cranks. NEVER had a problem.

rebuilding the hand crank-F20

SDE

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AlanA

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Andy Martin

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AlanA

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SDE

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F-Dean

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F-Dean

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350 dave

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Farmallb

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