Also here's a VIN decoder for the engine/frame serial.
http://atvmanual.com/honda/79-atc-atv-vin-decoder
Here's a good place to look at exploded part diagrams. They also generally have
parts labeled for out of production or not.
https://www.partzilla.com/catalog/ya.../1983/ytm200ek
Here's the clutches, yep there's two of them. The lower one is the primary clutch, it's basically like a gocart clutch, as engine rpm increases, the more it grabs. This one is normal to slip until you get upto speed in a given gear. Ideally you want to cruise around with it fully locked up when possible, if it's slipping it means to shift into a lower gear. It's not a super major thing to go slow in say 1st gear putting around the woods etc, just no point in the extra heat and such going around in too high of gear.
These clutches will be worsening curve for sure
The other clutch is effectively the same clutch as a manual shift atv, like a sports quad (not CVT). With them there is no primary clutch, and the left handle bar lever is normaly the clutch. On this machine the shifter shaft is tied to it, so it basically pulls in the clutch when you shift gears. FYI, it's just like a stick car, let off the gas right before shifting, and after the shaft is centered again give it gas again. You can do it quick once you're used to it. I'm not sure how Yamaha is setup, but on Honda the right side cover has a "clutch adjustment" which basically adjusts how soon the clutch activates vs how far the shifter shaft moves. The
service manual gives specs on how to adjust. A little bit of a lurch forward is kind of normal, at least on my Honda's. If the idle is too high, it will lurch harder.
I can shift the bike fine as it’s like a dirt bike
https://www.partzilla.com/catalog/ya...tm200ek/clutch
For the engine oil/transmission fluid, typically atv engines only uses one fluid and it's shared between both. Best to check the
service manual for what it calls for, but generally atv oil or motorcycle oil is perfect. If you want to look at the specs on the back of oil jugs, you need the certs for wet clutches.
Speaking of
service manuals in the link above, you'd want to grab the YTM200EK manual. The manual is for the YTM200E, and the year/model of that product is "K" for 1983.
For a source for
parts, you can probably find most things on ebay pretty well.
For the steering stem bearings, I've heard the tapered bearings for Honda is a good upgrade, so I'd assume the same thing for the ones you found. Depending how the bearings are worn, you might be able to just tighten up the bearing race that's threaded on the shaft to get some of the slop out of it. If it's not smooth then the bearings should be replace though.
These machines are quite a lot different from a Polaris or any other machine with a belt drive setup (CVT). Should be an interesting learning curve for ya. Anyway, good luck with the machine, hopefully it's an easy fix up for you.