For those of you who follow us, you’ll know that we picked up a unicorn back in July 2020. For those of you who don’t follow us, the unicorn I speak of is an ultra rare, grey market import 1992 Yamaha TZR250RS. A scant 1000 of these left the factory in 92 and only a few have made it to these shores. And yes, we have our hands on one of them for restoration. The US stopped allowing the import of two stroke motorcycles in 1985 with the Yamaha RZ350. The RZ was and is a cool bike for sure, and it has quite the cult following. But in our opinion it doesn’t hold a candle to the TZR which is a street legal replica of John Kosinski’s 1990 250cc Moto GP championship winning racing machine. When we acquired our TZR it was it pretty good condition, although it was covered in light oxidization and didn’t run. Someone had wired the headlight switch to function as a kill switch, some form of anti-theft system we suppose. In addition, the previous owner tried to clean the carbs and mixed up the main jets when reassembling them making the bike run horribly once we got it started. Turns out he two carbs run different sized mains.
After several hours messing with the jetting we got the bike to run pretty well but Japanese market bikes are limited to 45hp and the CDI box killed spark at 9,000 rpm, red line is 11,000 rpm. It’s pretty frustrating when the bike falls flat at WOT when the power should just be hitting. We had to get the bike to rev to 11 grand. The easy answer is replacing the box with an after market, Zeeltronic unit. All it takes is a handful of dollars and you can rev as high as you like! While we were at it we installed a fresh set of rings and honed the cylinders. We also passed the engine parts through the bead blast machine to refresh the finish. You might be wondering, what good is having super clean engine parts with nasty nuts and bolts? We re-plated the nuts and bolts and any associated hardware making the engine look factory fresh.
The 280mm front brake discs were showing signs of wear and were slightly warped. We replaced them with a set of aftermarket hoops measuring 320mm. The larger discs required an adapter, which we had made for us. While we had the brake system apart we disassembled the calipers, rebuilt them and covered them in slate blue Cerakote. We updated the brake master with a 19mm radial unit and finished off the brake system with Venhill lines front and rear. The wheels went out for powder coat and Michelin 2ct’s were installed for road use. As much fun as the TZR would be on the track, the thought of a possible crash would take all the joy out of any riding which is the reason we opted for Michelin’s. We rounded of the Cerakote with the upper triple clamp and clip on handlebars. The last thing was repainting the OEM exhaust which will eventually be replaced with a stainless set.
If you are in the area, this bike is worth checking out, pop in and say hi!