1975 DT250 Looking for correct ignition coil

I need to purchase a new ignition coil for my project bike. The one that came on it had a very crispy spark plug lead which snapped when I was moving things around.

There are two different part numbers listed for the coil in the parts diagram. Does anyone have any guidance on which one I should search for? Speed and Sport Inc. has both listed as available, one is quite a bit more expensive than the other. I have the original but it doesn't have the Yamaha part number on it. It is stamped F6T409 and it looks like it was manufactured by Mitsubishi, or at least it has a similar logo.

The Speed and Sport parts numbers match the parts list numbers as follows:

5G4-82310-40-00 IGNITION COIL ASSEMBLY J17-823 email $116.55 (it may be that this part is used, it isn't really clear)
498-82310-40-00 IGNITION COIL ASSEMBLY $186.45

I see the 498 one available on ebay for $80 but it simultaneously says it's new and being sold "as-is" and hasn't been tested. The pic of it looks pretty used so I'm a bit hesitant. I had already purchased one from Partzilla but I screwed up and made an assumption on a part that looks right but had a different part number and it doesn't get the correct resistance readings. I'm a bit out of my element with the electrics. Any help would be greatly appreciated.



Thanks,
Mike

For the second "5G4" part number, I found this one, also on ebay, and it says it's compatible with 1975 DT250. It's only $10. Too good to be true?

498 ignition coil is the factory unit for the 250 .
The other option will be for the 400 , which has a CDI ignition , and a different output requirements .
The Ebay option might work , but is most definitely not a factory unit .
Some of the cheap Chinese units are a bit Hit or Miss .

That looks pretty good and affordable. I can fabricate like a banshee but have a tough time understanding wiring. I did just pull the trigger on the expensive one with the correct part number from speed and sport but might cancel if you think the Emgo is a good option. My little $200 barn find is starting to get expensive! Thanks to both of you for the advice!

Mike

Is your spark plug lead replaceable buddy? Sometimes they are threaded into the coil.

Good question. I think I looked at it and thought it wasn’t replaceable but maybe I didn’t try to unscrew it. I did try to test it but wasn’t sure I was getting the right readings. Being a bit of a novice, especially with the electrics, my tactic has been to just replace with new, that which I don’t understand.

Probably not the best way to learn. If I can get the old one off, and if the coil tests okay, can I use any spark plug wire or is there anything specific I need to get?

Another related question, is it common for the spark plug cap to go bad? I tested it with a test light and it passes current but dimly. Is that something that has a resistance rating I need to check?

I am not familiar with your model & only asked as that is the case sometimes. The local auto part store here sells it by the foot for those wanting to make up their own cables