Timing

[TateBauer]

I got 1947 H and I’m trying to retime the magneto but I’m having a problem with the time pin lining up with the marks on the crank pulley when the #1 piston is at TDC. Has anyone ever had that issue? Thanks!

 

[stevieb49829]

Not much can be off between the piston, and the marks. Is the pulley on tight and on the key? How do you know you are at TDC on the piston? steve

 

[TateBauer]

I pulled the spark pull and rotated the motor until the compression stroke. I’m hoping the pulley is tight and the key is in. It’s a new to me tractor so I’m trying to work the bugs out.

 

[Janicholson]

I got 1947 H and I’m trying to retime the magneto but I’m having a problem with the time pin lining up with the marks on the crank pulley when the #1 piston is at TDC. Has anyone ever had that issue? Thanks!View attachment 5626

Put a cotton ball in the outside of the spark plug hole and rotate the engine with the fan blades (all plugs out) till the cotton pops out. Then put a plastic straw in the spark plug hole and turn by hand until the straw is as far up and nearly stopped. Watch the marks to check alignment with the position of the straw. they should be accurate. The timing is to be at TDC when the MAG impulse clicks, so it is necessary to time the mag, install it so the rotor is pointing between the #2 plug wire terminal, and the #1 terminal. Loosen your mag up just enough so that you can just move it by hand and push the top of the mag towards the block. Now crank the engine over through two revolutions until your on TDC again, at that point carefully rotate the mag away from the block ever so slowly until you hear the impulse coupling release. Stop right there and retighten the mag. Jim

 

[used red MN]

Hello Tate, welcome to YT! You said, “rotated the motor until the compression stroke” and what else? The question you have posed requires some more concise information. You will find on these forums you will often be asked to give more information or details. The cylinders compression stroke includes approximately 180 degrees of crank rotation. Also always please remember you are there looking at it. The only thing we see are your words. So as Stevie has asked what are you using to determine the location of the piston. It has to be at the very top of its stroke for the first mark of the two close together to be aligned with the pointer. I see someone else just posted, we shall see if we duplicated.

 

[Janicholson]

Hello Tate, welcome to YT! You said, “rotated the motor until the compression stroke” and what else? The question you have posed requires some more concise information. You will find on these forums you will often be asked to give more information or details. The cylinders compression stroke includes approximately 180 degrees of crank rotation. Also always please remember you are there looking at it. The only thing we see are your words. So as Stevie has asked what are you using to determine the location of the piston. It has to be at the very top of its stroke for the first mark of the two close together to be aligned with the pointer. I see someone else just posted, we shall see if we duplicated.

With respect! The first mark (rotating the crank clockwise from the front of the tractor point of view) is advance in my opinion. There is no need to fire when the piston is going down, Jim

 

[used red MN]

With respect! The first mark (rotating the crank clockwise from the front of the tractor point of view) is advance in my opinion. There is no need to fire when the piston is going down, Jim

Okay Jim, I did a little checking before I posted that. What I said about the first mark that passes the pointer being TDC was quoted from a reply by Pete23 in this post. YT post in Farmall timng
However, it looks like I may have not read far enough because there is some other controversy later in the post. If I have to bet on something about an IH and Pete 23 said it is so, my money goes with him!

 

[TateBauer]

Thanks for all the input guys! I for sure have the number 1 piston at TDC and the marks still don’t line up. Rotated the motor by hand clockwise looking from the front of the tractor. put my thumb over the spark plug hole and felt the air come out on the compression stroke I can visually see the piston in its TDC position.

 

[Janicholson]

Okay Jim, I did a little checking before I posted that. What I said about the first mark that passes the pointer being TDC was quoted from a reply by Pete23 in this post. YT post in Farmall timng
However, it looks like I may have not read far enough because there is some other controversy later in the post. If I have to bet on something about an IH and Pete 23 said it is so, my money goes with him!

Well I do believe you (and Pete 23 ) are correct!!!!! My brain overthought the idea and because the distributor turns the opposite, I made a mistake. Jim

 

[used red MN]

You sure the piston will not go up more if you turn the crank more. As the piston comes up and stops at top of its travel and then starts back down it has passed top dead center. If the crank is turned to line up the TDC marks and the piston has pulled back down then the key was left out of the front pulley or by some rare occurrence has sheared. You might have special pistons with high compression domes that were put in original distillate or kerosene burning engines to raise the compression that are sticking up in there you can see them through the spark plug holes. The combustion chambers in those heads were real deep.

 

[Janicholson]

To find the real TDC with science, Take an old sparkplug and crack out the ceramic. drill out the remaining for threads of some common size Screw a bolt in the new threads that sticks out far enough for the piston to hit it. Turn the engine by hand until it stops against the bolt. mark the pointer position, then turn it opposite until it stops. Mark the pointer position. Now measure 1/2 that distance and that is for real TDC. Jim

 

[Janicholson]

Okay Jim, I did a little checking before I posted that. What I said about the first mark that passes the pointer being TDC was quoted from a reply by Pete23 in this post. YT post in Farmall timng
However, it looks like I may have not read far enough because there is some other controversy later in the post. If I have to bet on something about an IH and Pete 23 said it is so, my money goes with him!

From Glenster: The second mark is to set magneto timing. It retards the ignition timing so the engine doesnt kick back when hand cranking. Also, if you look about half way further around the pulley, you will see a mark by itself. If you line that up with the timing pointer, then look up in the weep hole in the bottom of the bell housing, you will see the grease zerk in the flywheel to grease the clutch pilot bearing.

 

[rustred]

the mag has to be timed to the first mark which is TDC. it is not clear how you are doing that, as you say u can see it at TDC. at TDC there is a couple of degree's where the piston sits still when rocking the crank back and forth. use jim's straw and rock it back and forth with the fan while holding the straw with the other hand. in the middle of that travel its called top dead centre. then check to see where your timing pointer is pointing to. should be on the first pully mark. that pulley is tight so i dont see how it can be moved. this procedure lines up the marks perfectly as thats the way i do it when checking for piston tdc to the timing tdc mark.

 

[used red MN]

The piston stop that Jim explained is the final word on finding “TRUE” TDC. Not sure if it needs to come to that for this application. It would be the only method I would use if the pulley actually needs to be re-marked. The only other thing would be if someone who didn’t know what they were doing was dinking around with a chisel on that pulley.

 

[rustred]

the mag has to be timed to the first mark which is TDC. it is not clear how you are doing that, as you say u can see it at TDC. at TDC there is a couple of degree's where the piston sits still when rocking the crank back and forth. use jim's straw and rock it back and forth with the fan while holding the straw with the other hand. in the middle of that travel its called top dead centre. then check to see where your timing pointer is pointing to. should be on the first pully mark. that pulley is tight so i dont see how it can be moved. this procedure lines up the marks perfectly as thats the way i do it when checking for piston tdc to the timing tdc mark.

From Glenster: The second mark is to set magneto timing. It retards the ignition timing so the engine doesnt kick back when hand cranking. Also, if you look about half way further around the pulley, you will see a mark by itself. If you line that up with the timing pointer, then look up in the weep hole in the bottom of the bell housing, you will see the grease zerk in the flywheel to grease the clutch pilot bearing.

The piston stop that Jim explained is the final word on finding “TRUE” TDC. Not sure if it needs to come to that for this application. It would be the only method I would use if the pulley actually needs to be re-marked. The only other thing would be if someone who didn’t know what they were doing was dinking around with a chisel on that pulley.

yes , if you want to get all technical about it. my way works for the beginner, cause if the marks are out you will see it plain as daylight. you guys make things so complicated for a very simple solution for a beginner. and if yes the marks are way out to lunch then the time can be taken to make new marks his way.

 

[rustred]

this is the instructions for a magneto on an H.

 

[used red MN]

yes , if you want to get all technical about it. my way works for the beginner, cause if the marks are out you will see it plain as daylight. you guys make things so complicated for a very simple solution for a beginner. and if yes the marks are way out to lunch then the time can be taken to make new marks his way.

I agreed with what you said here “if the marks are out you will see it plain as daylight” that is why I said “Not sure if it needs to come to that for this application”
I am going to quit with that until the original poster comes back with more information. Otherwise this will be another one of those threads where the OPs subject and purpose of the post gets buried.

 

[used red MN]

Ah, very good RR! It seems the gurus were a little confused about the second mark. Now I will be waiting for something more from the OP!

 

[TateBauer]

Folks I used a straw and verified it at TDC but the marks are still off. At TDC The marks are at the 12 o’clock position on the pulley and the pointer in the 2 o’clock positions looking at it from the front. 1/8 turn or so of the crankshaft past the pointer when it is at TDC. Other then pulling off the pulley to verify it is on with the key in the proper position i have tried everything y’all told me to do and still I end up with the same results.

 

[Janicholson]

Well that is the last straw! I would mark the pulley flange with a white marker using two stripes with a gap between where the pointer is indexed. (clean the flange so the marker stays put). then set the timing as discussed. over the next months of operation, check the position again by (disconnecting the plug wires and turning the engine past #1 firing to see if it slips. If not its good to stay that way. Someone probably didn't put the key in the snout, and just put the pulley on it. SO the next time you need to remove the front end to do drastic repair you can fix it with a new key """ if ever""". Jim