Timing a H

[susandiane]

Friend has a 42 H with Fairbanks Morris magneto. It's in the shop for a general tightening up. Where are the timing marks on this beast? It was removed without bringing #1 to TDC. Crank won't engage crankshaft. Can engine be turned via PTO or pulley? Any advice will be useful and appreciated. Friend knows zip about this tractor and I know a bit less. Thanks!!!

 

[rustred]

on the front pulley the same as all these models. yes turn with pulley till #1 is on compression at TDC with the marks lined up. get the mag slot lined up so rotor is pointing to #1 wire and bolt it in. the fine tune till with the mag slots it fires at top dead centre.

 

[Dave41A]

(quoted from post at 00:20:16 08/24/21) Friend has a 42 H with Fairbanks Morris magneto. It's in the shop for a general tightening up. Where are the timing marks on this beast? It was removed without bringing #1 to TDC. Crank won't engage crankshaft. Can engine be turned via PTO or pulley? Any advice will be useful and appreciated. Friend knows zip about this tractor and I know a bit less. Thanks!!!

There should be timing marks on the front crankshaft belt pulley. There should be a pair of notches on the rear rim of this pulley. There is a pointer/indicator on the front of the engine that points at this pulley. This looks like a spike about an inch long, pointing at the rear pulley rim. The timing marks are hard to see as they are pretty small. The first one you come to is the TDC mark. Let me know if you need a picture.

Also, I think the H's all had IH-built H4 magnetos. If yours is Fairbanks, it is a non-standard install. You'll need to know this to time the magneto to the engine once at TDC.

This post was edited by Dave41A on 08/23/2021 at 05:58 pm.

 

[S.Hess]

It's been 20+ yrs since I had to time my He's, bit the timing line is on the crankshaft pulley. Your going to have to clean the black grease and dirt off the pulley to even see the line and then you will want to chalk or paint a white strip into the line to make it better seen. As for the crank, they tend to rust solid from lack of use and grease. Most of the time with lots of penetrating oil, wire brushing, pounding, heating of the stuck shaft, and cussing, one can get the old hand crank shaft to move in and out again so you can turn the motor over by hand. (If one can get a hand crank). If your not to worried about the condition of the shaft, I'd weld a 3/4 in or bigger nut of the front and hit it with an impact. The added benefit of the welded nut will always you to put a breaker bar on the front end where you will have better leverage turning the motor over by hand to get #1 to tdc

 

[Janicholson]

Well The timing is set at TDC. TO get there, you need a McDonald's Soda straw, and a cotton ball. Jack up one rear wheel and put it in 5th gear (or highest work gear if on steel). Remove the plugs is easiest to turn the engine. Put the cotton ball (gently and not too far) into #1 plug hole (radiator end of engine) turn the rear wheel forward until the cotton pops out, don't suck it in. Put the straw in #1 spark plug hole (it will not fall in) slowly turn the engine forward until the straw is sticking out as far as it can. Back and forth is OK to get it on TDC compression. Now find the timing marks mentioned in the other posts, and line them up. Now you know you are on TDC. The mag has a impulse coupling in the drive that spins the mag fast to produce enough electricity get it to start. The normal process is to put the mag on the drive so it is adjusted to be as close to the engine on top as it can rotate in the slots. Then rotate the engine 2 full turns to TDC again (be careful not to turn one or three) You will hear the mag impulse trip 3 times before the timing mark is aligned. Don't go past TDC. now turn the mag in its adjustment slot until it clicks the impulse, and tighten it down. All done. The TDC timing is only for crank starting, and is intended to keep cranking injury to a minimum from kickback. As soon as it starts, the impulse stops working because the speed is enough to make spark. The timing changes to full advance when the impulse is not tripping. I think you will find the second notch aligned for TDC as the other one is running timing, advanced. A third notch near opposite of the two is used to align the flywheel for greasing the pilot bearing once a year, if I recall correctly, through a hole in the bell housing. Manuals ar your friend. YT sells them. Jim

 

[BarnyardEngineering]

An H engine should be easy to turn by the fan pulley, even with the spark plugs installed. If the belt slips just push in on it with your knuckles to tighten it up and turn the fan pulley with your other hand. Removing the plugs will make it even easier.

The timing marks are on the front. The magneto can only be installed two ways. One is right, the other is 180 degrees out. It's not like a battery ignition where the distributor can spin 360 degrees. It has limited timing adjustment so you need to be close, and you can only help to either be close or 180 out.

BTW you don't have to know anything about "this tractor," just some basic knowledge of how a gasoline engine works and basic mechanics. No matter what color the tractor is, they all work by the same principles.