Hi all,
I am after a few ideas…got a highly tuned 177 P range engine which at the moment is running standard gearing.When I get to top-end the engine is still producing power but the revs are not being converted into more speed.I was gonna just change the whole lot for a P2 gearbox,anyone else done anything different? I want to be hitting high 70s for motorway use
Suggestions please!

Have you put on a cosa clutch with 21 tooth cog?

You could try a 21 tooth cog and a p2 4th gear, not sure if it will fit, but it does the other way around.

Are you sure it will pull with a p2 4th and 23 tooth cog?

Hi mate
Yeah had a look at the gearing link thanks.To me it looks like the only way to get the absolute top end and make use of the work that has been done to the scoot is the P2 gearbox,may be a lot of messing around but got to be the easiest way to get to 80+mph…dont you think?

I’ve got a px 125 with a malossi 166, reedvalve, etc. Taffspeed dyno tested it at 18.5 hp and I run it with a p200 primary and T5 fourth gear. The Cosa 21 tooth drive is too low and the 23 doesn’t fit without changing the primary. With the gearing i’ve got I get 70mph at 6500rpm (via revcounter) and a top of 85mph at 8500rpm. The gearing all depends where your engine makes its power. My scoots main powerband is 6000rpm-8000rpm so it’s ideal for motorways, my Mk1 T5 has quicker acceleration but revs out at 75mph screaming it’s head off. So it depends what you want to do, motorways or streets. The engine will rev to 9500rpm in the lower gears but not in 4th. [:dance3:]

hmm sounds mighty expensive.

There is a gearing calculator over at maybe you can work something out from that.

Well it makes more power than a standard P2 so that has got to be a yes…hasnt it?

Hello mate
I did think of changing the clutch drive cog to a 21 tooth but that would only give me about 5% improvement which would be a pity as the engine is capable of giving me more than that so hence swapping the entire box for a P2 one,I reckon the scoot will have enough power to pull from 3rd to 4th without to much trouble