Later engine in older chassis

[oldrider]

Installing a 1983 motor with tci in a 1979 special chassis. How do I hook up the electrical from the motor? What extra components do I need?
If possible, I would like to get a list of parts and a wiring diagram showing how to integrate any new parts into the existing 1979 harness. Also, what existing electrical stuff can be removed. Someone must have done this type of installation before.
I am new to this site and there looks to be a vast amount of knowledge available here for these bikes. Any help is greatly appreciated.
Thanks.

 

[jetmechmarty]

I’m doing the same thing.
https://www.xs650.com/threads/xs6502f-xs650sk-mash-up.58192/
I’m using the entire’83 ignition, battery box, and wiring harness.

 

[5twins]

You will also need a different regulator as the brushes on the '83 are wired differently than the ones on the '79 were.

 

[oldrider]

I’m doing the same thing.
https://www.xs650.com/threads/xs6502f-xs650sk-mash-up.58192/
I’m using the entire’83 ignition, battery box, and wiring harness.

Thanks for replying to my post. I bought a junk 79 special with a seized motor along with a 78 standard, more or less complete about 25 years ago. Also got a motor that was supposed to have about 6500 miles on it. All in the back of the garage until now. Picked up a pretty complete 79 special with a trashed motor about 5 years ago and stored that too. Time to start the project, going to put the good motor in the 79 special frame, but didn't realize the motor is an 83 with tci. So, I guess the best approach now is to get a new 83 wiring harness along with any electrical components that go with the later system.
Any suggestions on where to get parts?
I've been riding for almost 60 years, lots of bikes over the years. Have two antique Triumphs now and always wanted an xs650 as well. So, time to make it happen.

 

[jpdevol]

Just a thought; if points is not a deal breaker for you, it would actually be easier and cheaper to switch the '79 electrics on to the '83 motor. The only touchy part is ensuring the advance rod bushings are fit into the '83 camshaft properly. That way the harness, stator and all components work from the '79 chassis

 

[oldrider]

Just a thought; if points is not a deal breaker for you, it would actually be easier and cheaper to switch the '79 electrics on to the '83 motor. The only touchy part is ensuring the advance rod bushings are fit into the '83 camshaft properly. That way the harness, stator and all components work from the '79 chassis

Thanks. On closer looking at the wiring, it's pretty bad. PO told me when I bought it "there were some electrical issues". He wasn't kidding so I think it would be best to rewire with an 83 harness and components. The 83 motor looks pretty good, and I do like electronic ignition. Plan is to give everything a good cleaning, put it back together, get it running and not worry too much about cosmetics for now.

 

[jpdevol]

To convert the '79 chassis to OEM TCI you'll need a type A regulator and rectifier, the TCI Igniter unit and the associated wiring for those. The reg/rec: https://www.xs650.com/threads/diy-reg-rec-5twins-and-jim.55842/
The Igniter is an Ebay thing (used), or https://www.xs650.com/threads/gonzo-turns-one.59646/
Also a dual tower ignition coil

 

[jetmechmarty]

To convert the '79 chassis to OEM TCI you'll need a type A regulator and rectifier, the TCI Igniter unit and the associated wiring for those. The reg/rec: https://www.xs650.com/threads/diy-reg-rec-5twins-and-jim.55842/
The Igniter is an Ebay thing (used), or https://www.xs650.com/threads/gonzo-turns-one.59646/
Also a dual tower ignition coil

I’m using all of the ‘83 electrical components in mine. I’m also using the ‘83 battery box as it has proper mounting points for the later electrical components. Fortunately, I was able to buy an ‘83 bike for $50. That made doing this a no brainer. The ‘83 frame was ruined.

 

[jetmechmarty]

I have a spare ‘83 battery box if you want it.

 

[oldrider]

Still not sure what I'm going to do. Going ahead with cleaning everything and getting the 83 motor in the frame. Would like to go with the tci that's on the motor, but I may go with the suggestion to take parts off the 79 motor and use that.
Also, I have a 78 xs650 standard that I think only needs a gas tank and battery to run, along with a massive clean up. I've been retired for a few years and after other projects am getting back to my bike addiction.

 

[jetmechmarty]

I've been retired for a few years and after other projects am getting back to my bike addiction.

You need something to keep you occupied during those long winters. The couch is not healthy.

 

[oldrider]

Thanks to jetmechmarty, jpdevol, and 5twins for your info. I think, for now, I'll pull the points, advance unit and alternator stuff off the 79 motor and use that. I want to get this all back together and see if it will run before I get carried away. PO made a mess adding in line fuse holders so plan is to get a small fuse box an convert to blade type fuses a use proper connectors instead of twisted wire ends and electrical tape. The deeper I go, the more little things I find that need fixing.

 

[jpdevol]

If you need wiring repair supplies, here's a couple good sources that equal OEM specs.
http://www.vintageconnections.com/
https://easternbeaver.com/Main/Elec__Products/Terminals/Open_Barrel/open_barrel.html

 

[oldrider]

Well, moving ahead with the plan to swap the points ignition components from the 79 motor to the 83. Planning to use the 79 carbs after a thorough de-gunking. Got the linkage and slides working well, next to the float bowls which I suspect are pretty nasty as well. I have a feeling someone has been into the carbs before so will check for jet changes. PO installed a 2 into 1 exhaust, which I plan to keep. Also thinking of eliminating the stock air box and using separate filters for each carb. Any recommendations on filter brands?

 

[5twins]

Yes, get UNI straight foam pods, they work the best with these CV carbs. For the BS38, you'll want the UP-4200. No need for the special foam filter oil, it's actually too thick and can clog them. Just apply a light coat of a 50-50 mix of gas and motor oil. I use the cheapo Walmart brand of straight 30wt.

 

[jetmechmarty]

I followed the advice of @Vincenthdfan. Use the OE filter frame and cover it with Uni foam. You can buy the foam in bulk from Uni. I got mine from Dime City.

 

[oldrider]

Yes, get UNI straight foam pods, they work the best with these CV carbs. For the BS38, you'll want the UP-4200. No need for the special foam filter oil, it's actually too thick and can clog them. Just apply a light coat of a 50-50 mix of gas and motor oil. I use the cheapo Walmart brand of straight 30wt.

View attachment 243734


View attachment 243735

This sounds good to me, but, where do the vent tubes go that run from the top of the head to the stock air box?

 

[5twins]

As you can see in my 1st pic, I add power brake check valves to the breather hoses and poise them over the pod filter. If any oil does happen to come out, it will just be absorbed by the filter and/or be recycled through the motor .....

The intake end of this valve is a perfect fit into the breather hose.

 

[oldrider]

Gotcha. Thanks, saw that in the photo, but wasn't sure what it was. I think the UNI filters and this check valve will be a lot easier than dealing with the sock airbox etc.
The 83 motor is now in the 79 frame. Waiting on the rotor puller to make the points ignition swap.

 

[5twins]

No need to change the rotor, the newer style will work fine with the points. You can't go the other way - use an older points type rotor with the electronic ignition. The later rotor has a magnet embedded in it that triggers the pick-up for the electronic ignition. The points rotor doesn't have the magnet so it won't work with the electronic ignition.