Scooterotica

Hey,
My GT is on stock Jet200 gearing:
primary drive: 46/15
1st gear: 12.52: 1
2nd gear: 8.76: 1
3rd gear: 6.30: 1
4th gear: 4.82: 1

28mm Dellorto, breathsweet foam filter + PM tuning Evo pipe.

Pulls like its possessed up through 3rd gear and when I shift into 4th acceleration drops off dramatically. I have digital speedo so I can give RPM where each gear maxes out if that helps.

What should it ideally be?

Thanks in advance
David

I think your pipe is the problem, pm is a revvy pipe but your final drive ratio is better for a pipe that makes more torque, tsr evo or a fresco comes to mind, choice of pipe and final drive ratio go hand in hand. only other option is to get a bigger crownwheel.

holty wrote: ↑Thu Apr 25, 2019 7:48 pm I think your pipe is the problem, pm is a revvy pipe but your final drive ratio is better for a pipe that makes more torque, tsr evo or a fresco comes to mind, choice of pipe and final drive ratio go hand in hand. only other option is to get a bigger crownwheel.

... good response and almost certainly the issue.

Adam_Winstone wrote:

holty wrote: ↑Thu Apr 25, 2019 7:48 pm I think your pipe is the problem, pm is a revvy pipe but your final drive ratio is better for a pipe that makes more torque, tsr evo or a fresco comes to mind, choice of pipe and final drive ratio go hand in hand. only other option is to get a bigger crownwheel.

... good response and almost certainly the issue.

Thanks. So my final drive is 4.8 now, and it would be better at 4.9 with a 47 tooth CW?

Also, I have a bgm big box clubman on another scooter I could put on this one, what would be the correct final drive rAtio for that?

Tx
David

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4.9 might be a bit better but ideally you might want to drop it to 5.2 with that pipe.

The clubman might be a good choice on 4.8 what have you got to loose (other than an hour or two) by trying it.

There's nothing wrong with the gearing. The Jet pulled it okay with a 20mm carb and standard exhaust. Like others have said, it's probably the exhaust that's the issue.

Tx. Gearing is the only part of the engine I'm not that familiar with. I got offered the PM pipe at 1/3 the price of new so just tried it. Before I do anything else I'll throw the BB clubman on and see how it behaves.

David

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Davidsquaredson wrote: ↑Fri Apr 26, 2019 7:31 pm

Adam_Winstone wrote:

holty wrote: ↑Thu Apr 25, 2019 7:48 pm I think your pipe is the problem, pm is a revvy pipe but your final drive ratio is better for a pipe that makes more torque, tsr evo or a fresco comes to mind, choice of pipe and final drive ratio go hand in hand. only other option is to get a bigger crownwheel.

... good response and almost certainly the issue.

Thanks. So my final drive is 4.8 now, and it would be better at 4.9 with a 47 tooth CW?

Also, I have a bgm big box clubman on another scooter I could put on this one, what would be the correct final drive rAtio for that?

Tx
David

Sent from my Pixel 2 using Tapatalk

I'm pulling 4.6 with my GT200 and BGM clubman, Li150 46/17 so it should pull 4.8 comfortably

one of the chiselspeed /adspeed pipes would work well and pull that gearing ..if they still do them ...check with martin for advice though

Advice I have been given is Franspeed Race is ideal if it's >200cc, but the Supertourer is a better match for 200cc and my gearbox.

David

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