May be on to something or may be on something

[btdtdan]

I posted a thread a while back about my 81 special not wanting to go after much carb work and checking for other problem areas.
I have the good fortune of living close to another XSive owner and one heck of a mechanic. He stopped by and took a look at my POS and got to wondering about the TCI. Well turns out someone did a deed on this machine it has the old model 2h unit installed as opposed to the 4h unit it needs. We both agree this could be a significant cause for running like a sick dog.
Does any one have one of these units that they would sell or swap for a 2h?
Thanks,
Dan

[John]

Thanks Dan
To clarify Dan's point. His 81SH has a 2H7 ignition module on it, and from what my research has discovered is that it should have the 4R0 module that is specific to the 81 model. TC or anyone els who owns an 81, can you jump in and clear this up? What is the consequence of such a mismatch?

[steelcat]

I think that the 81SH did away with the mechcanical vacuum advance. If you had the older module you could get the bike to idle, but it would start to run crappy with any throttle. I think that someone the forum has done alot of research on the modules, but I think you need to fine one of the 4R0 units.

[nashville_bill]

My '81 Special's ignition module is marked:

Type TID14-04

4RO-10

[randy]

Steelcat is right, in 81 the mechanical advanced went away. The 4RO box has electronic advance built into the circuitry on in the TCI.

You have two options here:

1. Get a 4RO TCI box

2. Get a 2H7 mechanical advance unit.

HTH

Randy

[scoobes]

also check that your bike has a bal resister on it,if you have one then it is a different black box than if you did not have a bal resister if you get what i mean.

[sixtysix]

I think the coil primaries were different too, as long as you run the newer coils with an older box you are ok, but older coils and a new box will cause problems (overheating of ignition box).

[Bill__Woods]

My 81 has the 4R0 box on it. I wouldn't mess around with trying to make the incorrect module work, just get a used correct ignition box from someone here on the forum, ebay, or your local bike salvage yard. I have seen several 4R0 boxes sell used for $45.00 to $100.00.
Gary is correct about the 81 coils being unique to the 81 model.

[btdtdan]

TCI for my 81

Thanks for all the input. I am searching for an 81 4RO.
From all you have told me that should make my POS run like a good one. Holler if any one finds one or has one.
Thanks
Dan