Electrical Conversion Help Needed

[geneborg]

I have a '81SH Frame & Harness (much of original electrical components had been removed) and I replaced the '81 Engine (seized) and installed a '79SF engine. I have replaced the electrical components (from Andreas Weis) vintage about '79.
My question: I have the electrical diagrams and the harness hookup shows differences between the '81 and '79 especially concerning the "Ignition Unit".
The label on the Ignition Unit I have is: Hitachi Ltd, Type TID14-01, 2H7-10. How different are the Ignition Units between model years?
Is it possible to use the '81 Harness or should I go to a '79 Harness? I have started the hookup and am concerned about pushing my technical knowledge envelope.
gene borg in FL

[Crazcnuk]

The 81 ignition module is different than all other years. It incorporates the mechanical advance into the module.

However, as far as I know they all plug in the same.

Only other differences I know of are, the 81 doesn't use a ballast resistor for the coils, and will have a 4-way flasher switch on the left handlebar, where the 79 doesn't.

Other than that I think they are the same. Someone will chime in and correct me if I'm wrong.

[DiverRay]

Gene,
Your ignition box is the 78 to 80 unit. It will work as a plug and play with the engine you have. Looking at my Yamaha service manual, the unit should be a plug compatible with the newer wire harness.

[Rasputin]

I also have a 81 with a 79 engine in it. The bike came as a complete 81 except for the engine itself. The PO had not been able to start it after switching just the engine, so I got the opportunity to buy it.
I brought it home and switched the TCI out to the same one you have. It started right up and runs well. I have a few bikes and decided to shelve this one until later, so it has only been run long enough to know everything on it works.
I am going to follow this thread as I am very interested in hearing what anyone has to say about Crazcnuk's point about the ballast resistors. I wonder if it will affect the TCI (ruin) if I run the bike long enough without any ballast resistors in place. Other than that it is a simple plug and play to put the 2H7 TCI in there. Good luck.

[randy]

The 79-80 coils are 1.5 Ohms, the 81 are 3 Ohms.

All the XS TCI's need 3 Ohms on the coil primaries. You can either do this with '79 coils (1.5 Ohm) + ballast resistor OR with '81 coils (3 Ohm) without ballast resistor.

You can identify the 79 coils by closely examining the body. They have the words 'requires ballast resistor' embossed in them.

[geneborg]

Reply to Rasputin

Rasputin, you give me some hope. Does your 81/79 still have the 81 harness? If so, did you just plug in the TCI plug as it was on the harness? My TCI plug on the harness had fallen apart so I am not sure exactly how the plugs were aligned. I was planning on using a '79SF wiring diagram with the '81 harness and add the extra needed wiring. The '81 plug only has 5 plugs vrs the '79 with 7 plugs. I have wired in the ballast resistor already. The '81 came with the '81 harness but with most of the electrical components missing. I plan on checking my coils to make sure they have the embossed "requires a ballast resistor" on them.
In summary, I am planning on using the '81 harness with the '79SF engine, ~'79 electrical components, the '79SF wiring diagram and wire as needed as if the harness was a '79. Hopefully the '81 harness can be converted over to a '79???
Anyone else out there please comment to help both of us.

[Athedra]

Now this is where confusion strikes me. I have a '81 model. I have a mechanical vacuum advance and a ballast resistor.

[geneborg]

" Athedra Athedra is online now
XSive
Now this is where confusion strikes me. I have a '81 model. I have a mechanical vacuum advance and a ballast resistor. "

In answer, what '81 model do you have? Mine is an SH and it's harness has only five (5) wires in the main hook up to the TCI. This may also answer why I have seen different wiring diagrams for the '81 SH. One with the five wire hookup and another with the seven wire hookup, the same as the older bikes.
It appears they made some with the vacuum advance and obviously some with the electrical advance.
I am still looking to an answer to my question about using the '81 harness with wiring additions as necessary to convert it to a '79 harness.

[CatatonicBug]

Now this is where confusion strikes me. I have a '81 model. I have a mechanical vacuum advance and a ballast resistor.

What XS model is it? Are you in Benoni, South Africa? Not sure what models were available there. The RH in Australia has some interesting unique qualities as well.

[Rasputin]

"The bike came as a complete 81 except for the engine itself."
"Other than that it is a simple plug and play to put the 2H7 TCI in there."

I would go out and take a picture of the plugs to the TCI for you but I have that damn Swine flu, and a misbehavin computer right now. My harness and all electrical are 81 ....the Tci is 79...the engine is the only other thing that is 79. Hope this helps in some way.

[Athedra]

Yeah, sorry, we found that South Africa is 2 years behind the rest of the world. It is a '79 XS1100 (Post fix still to be figured out)...Apologies for that

[geneborg]

"The bike came as a complete 81 except for the engine itself."
"Other than that it is a simple plug and play to put the 2H7 TCI in there."

I would go out and take a picture of the plugs to the TCI for you but I have that damn Swine flu, and a misbehavin computer right now. My harness and all electrical are 81 ....the Tci is 79...the engine is the only other thing that is 79. Hope this helps in some way.

Do me a favor when you recover from the FLU and your computer is fixed send me that promised picture. I would be especially interested in being able to ID the wire colors. I am again with a '79 engine, '79 electrical components, and '81 harness.
I currently have things plugged in (seven wire) into the '79 TCI and all the electrical being of '79 vintage. (using a ballast resistor)
Anyone else with comments, let us know.

[DGXSER]

I got you covered Rasputin/Doug. I just happen to have my project 81 torn down to about the frame and in the process I have taken some pics of said connectors for another memeber.



Here is one with flash I think it got a little washed out but eother way, here it is also.

[Rasputin]

Thanks DGXSER. I was just getting the camera out to take a picture just like that. I still am having some issues with the computer but was going to download the pics to the wifes computer and then email it to myself. You saved me a bunch of hassle for sure. Now I just have to find the Banjo angles for Brake lines and get back to relaxing.

[geneborg]

Thanks DGXSER. I was just getting the camera out to take a picture just like that. I still am having some issues with the computer but was going to download the pics to the wifes computer and then email it to myself. You saved me a bunch of hassle for sure. Now I just have to find the Banjo angles for Brake lines and get back to relaxing.

The pictures are much appreciated but they show the '81 five wire TCI and not what I need for my '79 TCI and engine. I am again using the '81 harness and adding wires as needed plus the ballast for the '79 electrical needs resulting in the seven wire hookup.
You indicated that you had a '79 TCI with a '79 engine therefore don't you have the seven wire hookup to the TCI vrs the five wire hookup for the '81 TCI. I hate to be a pain but if you have the seven wire hookup I would still appreciate the pictures, if possible.
Thanks for the efforts. I have done a seven wire hookup and have indicator lites but have yet got power to the starter. I am still going over the wiring diagrams.