On the dyno Mugello 186 kitted Lambretta. On testing: bgm Clubman, JL KRP3, Style63

Today a customer and friend of Scooter Center popped in to see how the bgm PRO MRB Big BOx is performing.

The Mugello kit came in tuned to 128° transfer and 190° exhaust timing.

The carb is a 34 mm Koso and the ignition system fitted is the Varitronic.

The Style63 exhaust made nearly 29 hp.

If you compare the expansion chambers and the Big Box peak power wise they win.

But when it comes to a smooth to ride engine that is easy to hold into the power band than the Big Box is the winner again.

The ignition timing was set to 23°-15°, what is okay for the hig revving monsters. But even with that expansion chamber setting the Clubman out-performs the expansion with roughly 3 hp and 3 Nm more torque low down.

At around 5.600 rpm the JL and Style63 start to perform and double the horse power within a powre range of 1.000 rpm. Right for ‘general hooligan behaviour around twon’ to quote one of our favs from a Scootering exhaust test back from the ninties.
Steady acceleration can be found marked red in the dyno sheet!