I'm looking to get hold of a Gilera runner 125 or 180 LC engine, and i've noticed theres a few variants one with a rolling nut, one without and maybe some others which one is the best for 'tuning'? which one has the disc brake? Thanks
Any SP engine has rear disc, and FX/FXR engine is rear drum. The rolling nut engine is better for tuning mainly because its the newest 2T 125 engine you can get, and both primary & secondary gear up kits can be used, where as the series 1 & 2 can only take a secondary gear up.
