It's quite the saga but that YZF I had was a fully race prepped bike with a fully built race motor, carbon fiber body, Ohlins suspension, blip shift, full titanium catless Graves exhaust, quick shift etc etc. The story is that this guy had it up for sale for 8 months and no one wanted to buy an expensive race bike.
I got to ride it a few times fully race prepped with race gas, sticky tires, GP reverse shifting, super high rev, 3mm foam seat pads... etc... and I thought- as a race bike- It was incredible, so loud, hard riding, terrifying and scary fast!
He had bought the bike brand new and his mechanic had taken all of the stock parts off of it including the motor after like 10 hours... Put all the parts in bins, wrapped all of the body in cling wrap and put them in bins too. A very extraordinarily talented racer now in his early 60's but not a mechanical fellow... Since no one would buy it as a race bike he hired me to change it back to a street bike. And he sold the race motor separately.
This was a hard job to undo all this maticulous work done by his race engineer (a former helicopter mechanic.) Every fastener was titanium or aluminum, torque marked and safety wired. Every electrical connector was repinned with water proof deutchtech stuff. Race ECU and stand-alone shifter ECU wired so clean.
So minty.
It was a tragedy to take it back to stock. But I got it done and he posted it for sale.
After 6 months of holding the bike for him with only a couple of showings and not being paid: we agreed that I would sell the bike for him- surprisingly he brought me the title the same day. He was just in a bad place financially but an honest guy. I sold the bike, kept just what I was owed and gave him the rest. Then he gave me a good size chunk of his cut for my trouble- what a guy.
I always wished I had the means to keep it as a race bike and try my hand at track racing. But the prep costs alone would blow my whole desert racing season budget out of the water. (He told me he had somewhere in the neighborhood of 20-25k just in the motor- which he refreshed each season).
My warehousing guy bought the fresh (street bike version) for pennies on the dollar! He called me a few weeks later after he blew the head gasket when he overheated it bouncing off the limiter showing off at house party.
I declined the offer to have me fix it lol ---I'd had enough of that bike in my life.
8 or 9 months later- I think he's finally got it back together with just him and his father! But he covered in monster energy stickers...