There are parts manuals on pages 3 & 4 for your YM2000. They are added as attachments to each post where available.
YM1700 Originally a Tree Frog. 🤑 A real cheesy production logo. In a rare instance, a YM1700 Tree Frog restored to showroom new condition. This is a beauty. The machine was on a market place, the only image left in the cache to pull from. It would have been great to have more...
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YM2000A The A-model is a refresh upgrade. Did the YM240 go red at this time. YM240 never went to red paint so far as I know. The Donaldson-type air filter external on the left was one year, 1981, final year of YM240, and that's the only upgrade to series 2 (headlights in hood) that I know of.
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The YM2000 came is 3 generations plus an odd YMG2000 generation that is far different.
On the engine plate or body plate, does it read YM2000A or YM2000A-A?
Grab those parts manuals, look them over and see how the front axle it put together. The diagrams are a huge help.