Ignition coil bench test 1981 TCI XS650

Betatester

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Hi,
I'm completely new to posting so apologies if I'm out in the weeds, but here's my question. I just ordered up a coil on e-bay and am now wondering if I blew it. The stated OMS indicated on the primary side are 2. I'm seeing the appropriate reading of 2.5 in various threads here. Did I just waste $25 or is this within an acceptable range?
Thanks in advance
Quenten
 
First, welcome to the forum.
A TCI coil should read 2.5Ω ±2.5% @20°c ... 2.25 to 2.72Ω
So yeah... you're on the low side. If it's freezing you're pretty close.
Plus, good meter or Chinese crap?

On one hand I'd most likely run it.... but that's just me. :cautious:
On the other, that runs a bit more power across the transistors that charge the coil. TCI boxes are old and tired... plus they're rare as hens teeth. Worth the risk?

Got any info on the coil you bought?
 
First, welcome to the forum.
A TCI coil should read 2.5Ω ±2.5% @20°c ... 2.25 to 2.72Ω
So yeah... you're on the low side. If it's freezing you're pretty close.
Plus, good meter or Chinese crap?

On one hand I'd most likely run it.... but that's just me. :cautious:
On the other, that runs a bit more power across the transistors that charge the coil. TCI boxes are old and tired... plus they're rare as hens teeth. Worth the risk?

Got any info on the coil you bought?
Thanks for the prompt reply Jim, I appreciate it. Almost like I googled it.
Over taxing the TCI was my concern as well because I just purchased one for $125 so a little more painful than the $25 coil if I fry it. The coil was clearly a brain fart because I'm anxious to try and bench wire it and see if it'll lite up. I didn't receive it yet but the tag on it in the photo states it was tested at 2.0 OMS, and it's off of a 1982 XS650 Special, and an OEM component. No idea what quality of tester they used or the ambient temp but it was a fairly prolific seller. The photo is my 76 COVID project and the gateway drug to the rusted bucket of bolts basket case 1981 I just bought. Unless you count the 70 I had 48 years ago :)
76XS.jpg
 
I'd suggest you give up on the TCI coils... they're all 40+ yrs old now. I switched my '80 TCI bike to a Honda MP08 coil. Came out of a 90-something Gold Wing. It's a common mod a lot of us here have done. Honda used that coil in a gazillion different bikes. Prolly one of the best coils out there.
Here's 3 of 'em on Ebay. They used to be dirt cheap...


1679178471214.png
 
Sounds like a good option. I think I'll use the coil I ordered to see if I can get it to fire up just to put me over the edge and commit to the project, then go the Honda route.
Thanks again,
Cheers
Quenten
 
Oh thanks,
It was a great distraction project during the worst of COVID and had a cool back story. The seller had to go to assisted living and it sat neglected and hadn't run in many years. He was really pleased to see it running and, on the road again.
If you ever decide you want to part ways with that French Blue beauty let me know please.

Im in Olympia, WA and would love to get my hands on one some day. 👍
 
If you ever decide you want to part ways with that French Blue beauty let me know please.

Im in Olympia, WA and would love to get my hands on one some day. 👍
Hi Vincenthdfan,
I thought I replied to your post but either I didn't, or I don't know where to look for it. Regardless, at the risk of being redundant, you're just a few hours away and If I decide to sell I will definitely get in touch. I get attached to my bikes and always love to see them go to good homes where they'll be appreciated.
Cheers
Q
 
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