My 81 xs400s won't start. I've been working on it with my dad and he seems to think that the likely problem is in the ignition system. The spark seems to be too weak and wants to check out the TCI unit. The problem is that the Haynes shop manual that we are using for this bike is sucks and we can't figure out where exactly the TCI unit is so we can check it. I've tried googling this info in a million differents words and I can't come up with anything

I was wondering if anybody could provide any pictures or diagrams to help us find it and where we would get a new one if this is indeed the problem.

My 81 xs400s won't start. I've been working on it with my dad and he seems to think that the likely problem is in the ignition system. The spark seems to be too weak and wants to check out the TCI unit. The problem is that the Haynes shop manual that we are using for this bike is sucks and we can't figure out where exactly the TCI unit is so we can check it. I've tried googling this info in a million differents words and I can't come up with anything

I was wondering if anybody could provide any pictures or diagrams to help us find it and where we would get a new one if this is indeed the problem.

It's underneath the battery box, if you take the battery out you should be able to see it through the bottom slits of the metal battery holder. Also, if it's the same as the XS650's TCI unit, you can pick them up on ebay, there are two on auction at the moment.

Alright. My dad thought that was it but wasn't 100% sure (like I said, the Haynes shop manual for this bike SUCKS). Thanks a ton for the confirmation.

Now, does anybody know if I can use the TCI unit for an xs650? Those are the only ones I can find anywhere.