Both.

Page 55 of the attached document shows the US as getting an AT1J as well, with numbers in the right range? 

Intriguing.

Vintage Yamaha Enduro Fans - YAMAHA Model index -1958 - 2010 (yamaha-enduros.com)

Also, if a Japanese market bike, I don't think an engine number (other than maybe AT1) would be present.

I just realized I didn't answer your question.  In about 1974 in the US Yamaha started using the model code as the prefix for the VIN.

You might find a code in a casting or something, but it's not conclusive proof or anything as so many models shared parts.

One place you can look is on the left side of the carb across the edge of the flange where it bolts to manifold there should be a carb number stamped.  That could provide some information. 

I also see you posted pics!  Thanks!  What I do with Imgur is click on the photo in my account I want to post on the forum.


The photo opens in a new window.  Then I click on the "copy" button in the "BB Code" section and paste that link into my post by using CTRL-V to paste where I want it.







 

I'm slow. Good find in that book Gruncleal... I've never been sure that listing is official Yamaha... and even it is, what makes this difficult is Yamaha Literature often contradicts itself or is plain wrong.

You've been on this forum a long time... I've been here and on the previous US-only forum (owner of that site blocked IP addresses from other countries due to hacking concerns) and if in fact there was a USA AT1J model with a VIN that started with a "4", don't you think there would have been some posts about it? Or even an AT1M that started with a "4"?

Not conclusive proof but I have literally read every post on this forum and have never seen an AT1 or AT1M with a VIN number outside the published US range that was actually a US model. That's not "conclusive proof" by any means... just evidence that it's not too likely.

I asked for pictures of the frame and engine VIN... hopefully we'll get those... and then hopefully Enduronut will visit this thread and provide us with his expert opinion.

imgur.com/6zB1d99
i.imgur.com/q6tFGgq.jpg

Should my photo link end in jpg or not?

Go back a few posts...  I posted how I do it. 

imgur.com/DkA1f1h

imgur.com/dzfXozh

imgur.com/PcWApB0

imgur.com/GClgW1N

Thanks for photos, and good morning Mark.

I'd stick my neck out and suggest that the number stamped on the engine wasn't done by Yamaha, which points towards a bike brought back from Japan by someone who lived there for a while.

I agree that it seems very strange that neither Enduronut nor Devin has posted about this model.

The only time that I've seen reference to a 'J' model is when the odd part (usually a carb) has appeared on fleabay.

Photos of the whole bike would be good!

Photos up a couple of posts Uncle.
Looks nice too 1960Super10. Room for a "21 under the fork brace if you so desired.