Hand crank starting ,not happening.

[Eugene]

Check the timing with a timing light while hand cranking the engine. It will probably take two people.

This check is looking for a faulty impulse coupling or worn stud.

[Waif]

Hi,
You could check it with a timing light to see where it is firing, Jim B. was saying that a magneto should be timed so the timing mark on the pulley is about 1/2 inch advanced from the timing pointer, when running at low idle speed.
If the timing is right, and you replaced the points and other tuneup parts, I would check the spark, it should be blue, yellow is weak. The magneto coil could be weak and need replacing. TM Tractor has a new coil.

Hmmm , need to get a timing light then.
Per one manual...(IF magneto has a spark advance) low idle should be set to 375 rpm to stay below that point. ( Guess who does not have an rpm guage?).
Not safe to have spark before TDC , so going beyond is the only option to change current setting of tdc. Which is interesting because it should change where magneto trips?

New coil last fall.

[Waif]

Check the timing with a timing light while hand cranking the engine. It will probably take two people.

This check is looking for a faulty impulse coupling or worn stud.

What would a faulty couping or stud reflect in using a light , vs a good coupling and stud?

[Eugene]

You are checking to see that the spark and impulse coupling snap occur at TDC, compression stoke.

Something else to try, set the pointer about 2 degrees after the TDC pulley mark, then try hand cranking the engine. If the spark is occurring before the cylinder's TDC, probably never be able to hand crank the engine.

[Waif]

You are checking to see that the spark and impulse coupling snap occur at TDC, compression stoke.

Something else to try, set the pointer about 2 degrees after the TDC pulley mark, then try hand cranking the engine. If the spark is occurring before the cylinder's TDC, probably never be able to hand crank the engine.

Ahh. I' m catching on now. You are suggesting the spark may not relate to my hearing the coupling snap at TDC.


Taking a day off from it , but do not recall hearing coupler snap when pulling crank upward from six o clock to twelve o clock.
Could be from my grunting noise... but should still be note able.

[Waif]

Changed my mind about a day off.
My arm should be bigger than my leg...

The coupler does not snap when pulling crankhandle from six to twelve position. The stroke deemed most safe when thumb stays on finger side and body parts kept clear.

Throttle near a third ,half choke, and three quarters of a crank ( three to twelve o clock) revolution and she fired.
Bumped throttle up a notch and another three quarter crank( audible coupler snap) and the tractor ran.

[Glen]

Hi,
It would be good to check the spark, it should be blue. To do that, pull the ignition coil wire out of the distributor cap, and hold it 1/4 inch away from bare metal on the engine, turn the switch on, you might need 2 people to do this. Turn the engine with the starter, see if the spark is blue, then turn the engine with the crank, and see if the spark is blue. Then you will know if the spark looks good.
A new coil can be defective, or go bad in a short time too.

[Waif]

Thanks all.
Some rear tires are on order and the help to mount them might make a good volunteer to help with the spark check.

[Glen]

Hi,
The condenser can go bad too, then the engine can run bad, or not run.

[Matt Kirsch]

Do you have an original or an aftermarket crank. I seem to recall a while ago some cranks were produced with the cross pin at 90 degrees to what it should be. That would put the impulse stroke in the 3-9 o'clock swing, if I'm not mistaken.

When you lay the crank in the storage position on the platform, the cross pin should be vertical.

[Waif]

Do you have an original or an aftermarket crank. I seem to recall a while ago some cranks were produced with the cross pin at 90 degrees to what it should be. That would put the impulse stroke in the 3-9 o'clock swing, if I'm not mistaken.

When you lay the crank in the storage position on the platform, the cross pin should be vertical.

Uh oh...
After market crank. And now ,as Paul Harvey used to say ,the rest of the story.

I have great faith in my " tractor guy". Have seen his work and discussed tractors I am more familiar with.( He did own a cub among many tractors too). Then had him replace the transmission tube and clutch.
While at it I told him to order a hand crank.
He don' t like/ trust a crank and let me know ,but ordered one.
It came with too large a diameter pin to work and needed to be longer( he said when I picked up the tractor).
So he removed the larger diameter pin and added a longer ,smaller diameter pin at a right angle to the original.......
I was suspicious when the pin kept the handle from fitting through the bolster ,but thought there was a piece broke out from where pin fits maybe.

I just double checked and you are spot on!

Thanks. Now I know.
I'll be letting him know too.

[Waif]

Update.

Getting better.
60 degrees F. Cold start. Just below a third throttle , turn choke at carb on at about a quarter inch. Starts on third pull.

It wants a full crank circle rather than the three quarter ,( still have pin through handcrank in wrong position) but compression and my being gunshy of a kickback means trying to stay with a 3/ 4 turn. Would prefer only a half turn.

[Rick Spivey]

Does impulse coupling cause the engine to "jump ahead" of the hand crank right at the point the mag "clicks"? It shouldcatch and have a strong enough spring to pull the engine ahead of you slightly, and momentarily. If not, I suspect impulse coupling. It's only job is to retard timing when hand cranking while causing mag armature to spin faster through the spark making portion of its travel. Not needed if starting by starter.

[Waif]

Does impulse coupling cause the engine to "jump ahead" of the hand crank right at the point the mag "clicks"? It shouldcatch and have a strong enough spring to pull the engine ahead of you slightly, and momentarily. If not, I suspect impulse coupling. It's only job is to retard timing when hand cranking while causing mag armature to spin faster through the spark making portion of its travel. Not needed if starting by starter.

That's probably what I mean by compression.
When trying to turn crank from 3 o clock to 12 o clock it pulls forward ,with a kind of resistance to my cranking. At 12 o clock it is pulling past,making me say it wants more of a turn. Pulling is a good description of why.
I will need to listen for the click( s) better , but the spring type tension makes sense.
Thanks!

[Jim Becker]

Never push on a crank, pull it. For a "normal" crank, this means to put it in at 6 o'clock and pull upward towards 11 or 12 o'clock. If the cross pin in your crank is in the wrong direction, start with the crank at 9 o'clock and pull towards 2 or 3 o'clock. Brace your left hand on the hood and keep your right thumb next to your index finger. Keep both arms out of the arc of the crank handle. If you can't start it with only 1/2 turn pulls, fix the reason it isn't starting.