John Deere Model D Flywheel

[gscott]

Hello, My first post here. I'm restoring a 42 JD Model D. It was a mess when I got it from the PO. I'm having a problem with timing it. On the outside rim of the Flywheel there is a small arrow cast in to the rim. What does the arrow suppose to line up with. I believe the flywheel is on the wrong crankshaft spline. Thanks for your help, Gary

[FWurth]

I had hoped that one of our JD experts would have replied by now. But for what it's worth, I don't think you can install the flywheel on the wrong spline as one of the splines is different iirc. As the timing mark, it is the rear top of the case. But the IT shop manuals for that tractor are readily available, likely can find one on line or e bay.

[Wayne Riedlinger]

Did you make sure it is on no. 1 compression, hold thumb over sparkplug hole and turn flywheel slowly. A TDC the arrow? would be about center towards the rear and there should be a raised up little mark on the transmission housing. not sure about a 40 but we just did a 30 and it has a raised mark on the casting but our 45 has a plate with the top bent down to horizontal. google timing a JD- D and you will get lots of help including from this site.

[ronm]

I think on a 42 there will be a deeper cut spline in the flywheel that should line up with a brass rivet in one spline on the crank. A lot of those rivets are sheared off or fell out so may just be a hole...
In any case, the "LH Impulse" mark on the flywheel should line up with the mark on the case at TDC #1...

Edit: screw, not rivet...

[gscott]

Thanks for your replys. I hope more JD folks will reply to my post. I feel I'm just one of many just trying to keep these old tractors alive without previous experiences with restoring tractors. In my past I restored Model T's to Mustangs over the years. I'm wanting to show/drive my John Deere at the Tulare Antique Farm Show this spring. Hopefully the Margaretta Ranch Show as well. Have a Great Merry Christmas and Thanks Again to all.

[ronm]

i really think the arrow may be something added after the factory, not having seen a 42 for a while? Is this a hand start flywheel or electric?

[gscott]

It's an electric. The arrow looks to be cast in on the outside band of the flywheel. After reinstalling the flywheel the arrow, it's smaller than your little finger, finger nail. (After reinstalling the flywheel the arrow points to the outside edge of the governor. Worthless IMO lol.) The guy helping me works on tractors for farmers in our area but nothing this old. We started it today after confirming the flywheel setting. He said I need a 25 degree long lug Impulse Drive Cup so we can get more Mag adjustment to make it run better. I have a #3774 35 degree on there now. I've searched and can't find a 25. Would there be anyone out there that may have a 25 degree cup they would sale? Thank You, Gary Scott

[Wayne Riedlinger]

What mag do have on it?

[gscott]

It's a WICO Type C

[FWurth]

Some of these points you ask about are confusing to me. You need to get a parts book sepc book and be sure what is correct for that tractor, just guessing otherwise. Pictures would help. They were originally equipped with a Wico mag, not sure about the impulse lag, but the only tractors I ever ran across that required that high of lag was an Oil Pull. It sounds like the engine has been completely disassembled as some point, possibly they didn't get the gears back in time. If the general timing is wrong changing the mag won't help. You need to check if the timing gears are timed as necessary and get the flywheel on where it belongs.