swa45 wrote:
The BGM kit with a 60mm stroke (187cc) gets you to 123 degrees transfer timing (173 ED), and that's without packing the base. You'll get really good power, but at a much lower cost than Quattrini. The only possible downside is the exhaust port area and duration, which you may want bigger for a peakier setup. However, for mile munching touring power, 123 TD / 173 ED / 25 BD is an excellent spec.
I can't speak to how the BGM does with a 57mm crank, but I run it with BGM with a 60mm bell crank & 110mm conn rod on my LML. It gives me about 125 deg of transfer timing, 172 exhaust with a 5mm spacer, VForce4 reeds and a PWK 34.
It's amazingly torqe-y. Hard to keep the front wheel down taking off in first, have to lean over the bars shifting hard into second, too. I measured it at 23 hp a while back with the GSF Dyno app, and while I blew it up and had to rebuild since then, I think it's better now than it was then.
Max RPM's are really too much, with overrun, it'll rev past 10,000. Peak power is 7,000 RPM's.
I rode it yesterday at the Slaughterhouse rally here in town and other than running a little warm for the mild riding, which I put down to just having put the BGM back on the bike and not having the carb fully set up yet, it was rock solid. I thrashed it through traffic pretty hard on my way home and it was great for squirting through traffic and racing off the line at lights.
I also can't speak to the Magny Cours, but I'll solidly endorse the BGM as a solid piece of kit.