And related... It might as well go in this thread for someone to find in the future:
10 years ago on a prior YM186D I replace the u-joint at the front of the propeller shaft. I learned that is a rare u-joint, difficult to find. But it had one application, that led to various suppliers.
Here's my notes I wrote at the time:
These ATV U-JOINTS WILL FIT THE FOLLOWING
HONDA ATV models:
1985 ODYSSEY (FL350) REAR SHAFT
Part # ATV300
* These may fit other Arctic Cat models.
And that guy wanted $249 for it.
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Or see on Ebay under $50.
American CV
1985 ODYSSEY (FL350) Rear Axle Shafts Standard U-Joint
Price: $29.95
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And someone posted in a Honda forum that Honda used that u-joint for only a year or two because it was used at such an extreme angle that it was a frequent warranty repair. No other known applications. [to those Honda enthusiasts].
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EDIT, UPDATE, 2024.
Looking on eBay today I see this U-joint is now also listed as:
Universal Joint-U-Joint GMB 220-0045 fits 74-78 Nissan B210, $18. [so it should be widely available].
Then the application notes say the original driveline used non-replaceable staked u-joints.
Also some of the more expensive listings include spacers and clips, while one commenter said he had to find suitable clips elsewhere. (For his Honda application?)
YMMV. The kit for Honda that I bought, fit perfectly. As I recall, I re-used the original clips.