Need help troubleshooting 1950 H

PurdueAg

Member
I am trying to help my Dad get his 1950 H running. It was running okay several years ago when I bought it for him. I drove it several miles from where I purchased it and it was running and idling fine. Then we tore it down to do cosmetic restoration (we did not tear down the engine). It sat for several years while he carefully prepped all the parts and painted them.

He took the magneto off (H4, I think), to have it rebuilt. He also had the carb professionally rebuilt.

When he got the thing back together a couple weeks ago, and tried to start it, it didn"t sound like it was running right. There was an occasional backfire. It chugged, and eventually died, and the carb would leak gas from the drain at the bottom.

He noticed that the spark plugs on cylinders 2 and 3 were fouled.

We thought the timing was wrong, to start with, because he has never had a tractor with a magneto, so he didn"t know how to time it.

So I got my manual out, and we set #1 to TDC, then rotated crank one revolution until the pointer on the gear housing was on the first of the two marks on the pulley. We had the bolts on the mag loose and pulled the mag away from the engine until we heard the impulse coupling snap, and then we immediately tightened the mag down in that position.

Still didn"t seem to help, altough the 2 and 3 plugs didn"t seem to be fouling as bad, and we didn"t seem to have the drip from the carb. But the thing would still chug, require occasional choke to keep running, and then die.

Well, then I found out that when my Dad had the mag off, one of the rotor gears fell out, and he didn"t time it when he put it back in. I found the flat tooth on the pinion (smaller) gear, and I found the teeth marked R and L on the larger gear. I didn"t have the right book handy and initially guessed and put the notched tooth between the R and L. Now I know it needs to be on the R. We plan to do that tomorrow. Will this make a big difference?

Then I got to thinking about the alignment of the magneto gear to the timing gear. I noticed two marks in the magneto gear housing. I read in the archives that magnetos need to be aligned with dots on the timing gear, and that the marks on the timing gear can be found by placing a mirror in the hole where the mag attaches (if you don"t want to take off the gear cover). We stuck the mirror in there and found marks. Should we line these marks up with the marks on the magneto, or is it sufficient to just get the impulse coupling to snap at TDC and leave it at that?

Also, he messed with the governor adjustment at some point. Will the governor adjustment affect how the engine idle? If so, how do we get that set right?

Finally, is it possible that the trouble isn"t with timing or governor at all (or in part)? -- perhaps the valves are sticking for having set so long without being run?

Any help you could give on which procedures we should do and in what order would be GREATLY appreciated. Thanks.

Tony
 
It will run better with the gear on the correct Letter. It may also be that the Firing order is wrong. 1342 from the front of the engine. Check rotor direction, then find #1 wire, and be sure #3 is next in rotation then 4, then 2. Mag gap is .013" Jim
 
after you resolve timing issues make sure your valves are adjusted properly....i have seen the retainer nuts for the rocker arms back off. also if your valves did stick pull the valve cover and make darn sure your push rods are not bent.
 
Sounds like you're on the right track with the magneto.

I'd check what the others have mentioned here, but if that doesn't help, I'd take a closer look at that carb.

I haven't been on this site very long, but I still wish I had a dollar for every time I read here that somebody had a carb professionally rebuilt, and is now having trouble.

The way the engine is operating, it sounds like it's choked. Make sure your choke linkage is attached and working properly.

Dripping gas means you're floats are not doing their job. So if you continue having trouble, I'd take a look in there.
 
That"s what I thought! But it def has a mag, and the SN indicates 1950, and all cast codes corroborate. I told some guy at a tractor show that 1950 was too late for a mag, and he said, "oh no, they still had mags as well as distributors." So either he"s right or somebody put a mag on after the fact.
 
(quoted from post at 06:19:23 09/30/11) That"s what I thought! But it def has a mag, and the SN indicates 1950, and all cast codes corroborate. I told some guy at a tractor show that 1950 was too late for a mag, and he said, "oh no, they still had mags as well as distributors." So either he"s right or somebody put a mag on after the fact.

The magneto was available as a factory option all the way up through 1958 on the 350s and 450s.
 

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