mopguy wrote: Why are the Kawasakis made between 1973-1976 worth more than the ones made between 1977-1980?
SUPPLY!! They only produced 80,000 or 88,000? Z1-Z1A-Z1B models from 73-75. Don't know count on 76KZ900? But they mass produced the late 77 and up KZ1000's with rear disc brakes. A lot of those still around. That's why the 76 KZ900 drum rear is the next high dollar bike as you are seeing on eBay and Mecum auctions last year in 2019 & early 20. In Las Vegas.
And the Guys on this site doing some fine restorations like Mikaw Matt! and I see 3 or 4 others in progress.
Plus in the beginning, I'd say 1/2 of the Z1's were turned into Racing, Drag Racing, Side Hack, Dwarf cars, Choppers to say the least! I myself, trashed at least 25 bikes for drag racing, buying rusted ones for $100 just for the engine. Cutting up frames, blowing up 5-6 stock engines with a turbo from 89-94 I had tried. Scraping frames and stock parts. It's all about the supply and demand and inventory of the old motorcycles. The Daytona 24 hour race in 73 helped fuel the growth also. And believe it or not, ask anyone down under in OZ. That the "Mad Max" original Movie, the "Stone" movie helped for damn sure! It's up to you 40's and 50's year olds' to keep it going! Plus the world wide attention to the 50th anniversary approaching sure will be a big notoriety for the mighty Z! That's JMO. Then again? What do I know? I help by modifying stock parts from there original state, but on the other hand as I sold parts on ebay for 20 years, those parts helped the next guy put his Z / KZ together. Just yesterday, I ground down some 77 up fork legs and a 76 front brake caliper. And I'll find the picture of a 73 rear brake plate with no wear indicator on it that I customized to my liking!
I'll go get some phone pics.