Lack of ability I expect. Obviously cant set the timing or the carbs so what else is dodgy, looks like it might be a spit and polish resto only.
Form over function
" Are spare parts available for this model ? 29-Jan-13
A: Parts are scarce, as they are for any 45 year old Japanese two stroke. Bodywork & major components are generally only available from wreckers (again rare) but you can find a fair bit of mechanical stuff if you search hard enough. Do a worldwide Ebay search on Yamaha YDS5 & see what comes up - that will give you some idea. Some minor bits & pieces can be found at YDS Parts in Scotland. This is primarily a show bike now - it can be ridden of course, but regular riding will quickly devalue it. Seats, for example, are unobtainable & this one took me three months to remake, starting with a rusted out seat base & importing a foam core from California. Hope this helps"
Talking up the rarity methinks . Body parts and mechanical parts ain't that hard to find.
And the seat; he didn't even get in right - OEM the top is welded pleats. Didn't even bother to stencil 'YAMAHA' across the back of the seat . - but nice correct chrome trim. If you have the original it ain't that hard to have the top welded (although expensive). Is El Dorado still operating?