I have a couple of Ossa Yankee 500Z. One is complete, I dismantled it completely to redo it (in boxes!) and I sent the engine to Keith Lynas who did a great job at rebuilding it completely to the tune of $3200.00. This one has a title. The second one is a rolling chassis, no body, lower engine in, cylinders etc in a box, should be considered as parts. I have to many projects, no time and will not be able to ride it when finished (bad right arm now!). How much should I ask for? Thanks.
Only my opinion, you likely won't get what you have into them unless you can at least get the complete Yankee back together and running. If you can demonstrate that it runs, drives, etc, then you can swing for the fence. Really nice Yankees can go for 5-8K, especially with the additional parts you have described. Sounds like a great opportunity for somebody. Good luck with the sale of your Yankees!
Saw where a fully restored Yankee brought $5K at one of the big motorcycle auctions not too long ago. I tend to think of the Yankee much like my beloved Rokon 340: rare but not necessarily desirable.....yet
