48 Cub Magneto Timing Help?!

[staninlowerAL]

#1 Piston at TDC, BOTH valves closed, = compression stroke. Your timing mark on the crank pulley should align with the pointer.

[Rick Spivey]

It will be easy to tell you are at TDC with the cylinder head off, so I don't know of a reason you couldn't install the magneto and time it this way.

[Jim Becker]

You can install the magneto with the head off.

[farmergiffIV]

I've been still trying to time the magneto now as the manual says with the head back on and I am ready to do a systems test and run the engine. However, no matter how many times I try I can't get the magneto to time up with the engine. I've timed this properly yet it must have been almost 2 years ago now and I must be missing something here, I've watched a how to video and still can't figure it out.

Every time I do it now- I tried atleast 10 times today and I end up getting the magneto timed so it goes off about 2 inches past where it is supposed to based off of the fan wheel punch and alignment pointer.

In order for me to get the magneto to click on the cylinder 1 TDC, I have to take the bottom bolt out from holding the magneto in place and then rotate the top of the magneto even further away from the crankcase than what is allowed with the bottom bolt in. Yet when I then go to check if its align by double checking, its off and I hear a click after the wheel has passed the punch mark. I am pretty sure its supposed to click right on this mark though right?

When the engine is in 1 cylinder TDC the governor does indicate 8 and 2 o'clock so this appears to be correct ( I haven't adjusted the governor at all) What else could be wrong here?

[Don McCombs]

Are you sure you have the rotor and pinion aligned properly?

[farmergiffIV]

It seems like this would be the natural thing to have wrong here, but I have it set so its right about to trip on spark plug 1. Maybe I am doing it backwards but its pointing at 12 o clock, I could try it backwards maybe I am thinking the wrong side is up.

[farmergiffIV]

So I watched Hangel's youtube video again and I am stumped. I am doing everything I can see right, the only thing is, when I go to pull the magneto away from the crankcase after the second TDC alignment, it doesn't click. Does this indicate that the magneto or governor could be out of timing/alignment?

I am going to check if my cub has a punch mark indicating if the governor is in alignment. Also, I went to oil the magneto in the bearing spot there and pulled out a 3" long piece of what appeared to be felt! ? Maybe that is a problem.

[Jim Becker]

You previously said the drive lugs on the governor were in the right place at TDC. If so, they can't have gone anywhere by themselves. If you haven't already changed the governor timing, don't start now. You previously had trouble setting to TDC. Are you sure you are setting it at TDC now?

Your post from last evening suggests you are setting the rotor position by eyeball. Don't do that. Set it according to the marks on the rotor and the pinion gear.

Oil cups frequently have a felt insert to hold the oil and release it to the bearing as needed. I didn't check to see if the magneto oiler has one, but if you pulled one out, it probably needs to go back where it was.

[Glen]

Hi,
Here is a pic of how the governor gear and the drive slots should be turned at TDC. This is John's pic, I think.
The rotor and pinion gears need to be aligned like in the pic below, there is a mark on each one, the marks should be aligned. The gears should be greased also.

[farmergiffIV]

Just watched Hangle's video yet again, I will inspect the rotor and pinion gears.I couldn't imagine they would be out of line since I drove the tractor in and then parked it just before disassembly but I will inspect so see- mmm grease.

[farmergiffIV]

Hi,
Here is a pic of how the governor gear and the drive slots should be turned at TDC. This is John's pic, I think.
The rotor and pinion gears need to be aligned like in the pic below, there is a mark on each one, the marks should be aligned. The gears should be greased also.

Wala! One problem found. The rotor and pinion gears were out of alignment. They are now greased and reassembled.

However, after I looked more closely at the governor gear they are not at 8 and 2 o clock like they are supposed to be when the tractor is at 1st piston TDC at the mark on the fan pulley housing. The governor gear is actually in alignment with the stamped mark on my cub at 8 and 2 o'clock when the mark on the wheel is about 1 inch farther down the wheel when turning the engine over.

So another problem must be the governor then unless I'm missing somemthing. Does anyone know if I can I run the tractor like this or how do I get them back in alignment? I don't know how this could have happened while sitting for 3 months in the garage, I drove it in there, major reason I wanted to move it to the garage was the governor was acting funny, and tractor was getting harder and harder to start...hhmmm

[Jim Becker]

Does your pulley have 2 notches (about 3/4 inch from the first to second)? If so, TDC is at the second mark to reach the pointer. The 2/8 o'clock position is, more precisely, 35 degrees away from horizontal.

[farmergiffIV]

Does your pulley have 2 notches (about 3/4 inch from the first to second)? If so, TDC is at the second mark to reach the pointer. The 2/8 o'clock position is, more precisely, 35 degrees away from horizontal.

I am going to look really closely tomorrow- but unless its a faint notch that I havn't notice in the last few years I am pretty sure there is only 1. I am really suspect of the governor now. I think I'll remove the governor and inspect for damage, and then properly install and align at the TDC notch. Then hopefully she'll run.

I am so supprised the pinion and rotor didn't solve it, not sure if someone sneaked in my garage and messed up the magneto and then retimed the governor to be out of line...

[Glen]

Hi,
A 1948 Cub would probably have originally had 1 timing mark on the pulley, but the pulley could have been replaced with a pulley that has 2 marks.
Here is a pic of the Cub governor gear, from TM Tractor, showing the timing mark, it is on the left, on the edge of the gear, it should align with the mark on the idler gear in the engine, when the engine is at TDC.
If the oil seal is leaking, it is a good time to replace it, while the governor is out. Be sure the seal lip is facing ahead on the seal.

[farmergiffIV]

Well, I am very certain that the governor is now timed and the magento is properly set. The governor was out of alignment from what I could tell or somehow skipped out of alignment. I really have no clue how this might have happened.

With the new head gasket on I am ready to start this up but I am having trouble start the engine still- it's sat a few months and hasn't been ran in awhile so I- changed the oil and primed the oil pump well, until oil oozed back out. I double checked the timing on the magneto it appears to be timed just right it. But I cant get it started though, I've sorta dreamed of this thing just starting up on the first or second crank but I just seam to flood the carburetor every time.

I hear air being pulled through the air filter, and air coming out of the exaust as I crank it and I heard a small put put, but nothing major just a sound like it almost wanted to start but no take off- I've been following the directions on the manual on starting it in terms of choke engagement. There's got to be something I am missing.