The Derbi GPR 50 as delivered from the factory is a slug. 1st step, remove restrictor in pipe. Now we have a bike! The only limit on engine mods on the GPR50 is your wallet! With very little modification, this bike rips. With a lot of modification, (translation=$$$) it's un-beatable. Team Calamari does it all, from mild to wild. Your wish is our command! If you want to ride a winner, this is it. |
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Replace the small stock 14mm carb with a 24mm flat slide Mikuni |
Carb fits easily with K&N air filter |
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Stock radiator is quite good. We add a digital water temp guage (ideal temp is 65 degrees celsius) |