Pickup coil question

[dbeardslee]

Will the pickup coil assembly off an 81SH work on a 79F with the stock TCI?

[bikerphil]

Will the pickup coil assembly off an 81SH work on a 79F with the stock TCI?

Yes, it will. Same P/N: 2H7-81676-10-00

[dbeardslee]

Phil - When I checked the fiche it showed the part number for the 79 as 2H7-81671-10-00, but it showed the 81 SH as 4RO-81671-10-00. I saw another thread that mentioned swapping the coil baseplates to make it work with the 79 governor assembly. I've never done it so I just don't know.

[bikerphil]

Yep, I see that now, I was looking at just the pulsar coils. Don't know what the difference is, except the 80 and up are held on with those tamper proof screws. The springs in the centrifugal advance may be different for the Special model. The Specials run a 31* BTDC and the Standards are 36*.

[dbeardslee]

I wonder if it would work if I took the pickup coil bearing assembly out of housing and transplanted it along with the little pointer thing that fits over the end of the governor assembly into the 79 using the 79's governor?

[randy]

Yes, that will also work.

[dbeardslee]

Cool. Thanks fellas.

[Ivan]

As far as I can tell, the pickups themselves are the same. The differences are in the rotor and TCI. The rotor has springs for a centrifugal advance on the earlier models and a 81 has one. Also, the notch on the pickup assembly is wider on the 81 since the reluctor tab is wider. (might be the other way around tho). Any way, when mix and matching, you may have to grind the slot a bit wider.

[dbeardslee]

Here's a picture of the unit that's headed my way. It appears to have the reluctor (is that what you call that little pointer thing). What I was thinking was to just remove the pickup coil bearing assembly (sans the housing) from the center, put the reluctor on the 79 governor, and slide the bearing assembly over that. Then I can still manually adjust the timing and I can't see where I'd need to grind anything. That is assuming the 81SH reluctor fits on the 79 governor.

[randy]

No, keep your 79 reluctor, it has the mechanical advance. The only time you would switch reluctors is if you're switching TCI's as well. The 2H7 TCI needs the mechanical advance, the 4RO TCI doesn't.

[Ivan]

The one in the picture has the wide slot. I may have gotten it backward, so the early models may have the wider slot. The narrow one came with a reluctor that was just some stamped steel spot welded on the shaft, the wide ones were more of a cast looking piece.

In any event, the reluctor (the pointer) needs to stay with the TCI. The early ones used mechanical advance, and the later ones used electronic. An early reluctor with a later TCI would give you hellacious pinging troubles, and a late reluctor with an early TCI would give you no advance what so ever.

[randy]

Yeah....what i said.

[Ivan]

Yeah....what i said.

Yeah, what he said.

[dbeardslee]

What you both said . Thanks for clearing that up. So it sounds like all I really have to do is swap out the bearing assembly, gap the pickups, re-time and ride.

[randy]

While you're at it, you might as well lube that bearing. It's just a large diameter ball bearing and it can get grungy. DAMHIK!