Ignition Coil Resistance & VIN lookup

[GetTheExtractorReady]

Hey everyone,

I've got a 1981 XS400H (or SH, can't tell, all I know is it's an '81, which makes it one of those two).
First question - I have a cracked ignition coil, so I was planning on replacing both with the dual-coil from mikesxs (https://www.mikesxs.net/universal-12-volt-ignition-coil-fits-four-cylinders.html). In the manual for my bike, it says primary resistance of the coil is 4ohms, but the mikesxs one is 2.4ohm - will this cause any problems/perform any differently? Do I need to make any electrical accomodations for the lower resistance?

Second question - Do any of you know a good VIN lookup tool for older bikes? Every site I've tried can't find anything on my VIN (I've tried adding the leading zeroes to make it 17 digits, my VIN only has 9 digits).

Thanks!

 

[CaptChrome]

I can help on the VIN and model question, maybe.

XS400H will have a front drum brake, the SH will have a front disc brake.

Your 9 digit short VIN is made up of the model type code followed by the serial number of the bike.
Model type codes you might have include
4R4 - US market XS400SH from 1981
4R5 - US market XS400H from 1981
5E8 - Canadian market XS400H from 1981

The 17 digit long VIN consists of the following strung together:
JYA - designates Yamaha as the manufacturer
The model type code followed by two zeros, e.g. 4R500
A check digit (I don't know the calculation of this)
The model year code. A=1980, B=1981, C=1982
The plant of manufacture. Since all were made at the Iwata City plant, the code is "A"
The six digit serial number

Putting it all together you get something like JYA-4R500-7-B-A-123456 which would have been on the label on the headstock

Based on what you know, you can try a lookup changing the check digit until you maybe get what you are looking for.

 

[RadlagerMike]

Please take a look at the german forum here

http://xs400.net/wb/pages/ueber-die-xs400/xs-400-modelle.php?searchresult=1&sstring=modell#wb_13

 

[GetTheExtractorReady]

Thanks for the info, both of you! Going to see if I can piece together a valid VIN with what you’ve told me. I did notice that my model no. isn’t on that list. It’s a 4T4, which I guess is Canada specific. Hopefully it doesn’t complicate the VIN syntax too much

Now all that’s left is to figure out how important coil resistance is!

 

[CaptChrome]

4T4 is a 1981 XS400SH