Sx150 front sprocket

[Omega 7]

One of our club has just fitted a mugello 200 onto his sx150 but naturally it's now very revvy. It will still have the 15 tooth front sprocket on. By going up to 16 tooth would this sort it or does he need to go up more. It's his first scooter for years so he just wants something that works ok

[Avantone]

One of our club has just fitted a mugello 200 onto his sx150 but naturally it's now very revvy. It will still have the 15 tooth front sprocket on. By going up to 16 tooth would this sort it or does he need to go up more. It's his first scooter for years so he just wants something that works ok

Think I’d probably go up 2 to a 17x46 (81 link chain) to give you a 4.98 final ratio (up from 5.65)

Not a great box though - you could go lower on the ratio if the 3rd to 4th gap was closer.

https://avantone.wordpress.com/visualiser-lite/factory-sx150/

[Omega 7]

Thanks for the reply

[CHRIS in MARGATE]

I tried this. Not good. Bad box with big gap between 3rd and 4th that gets worse with a bigger front sprocket. Its not so much keeping the revs up before changing up but rather when you need to change down when encountering gradients or headwind. The revs rise dramatically so if you were riding at 60mph in top and had to change down quickly to "stay with the pack", the engine will rev like mad in 3rd
Not a good box for an expansion pipe but easier with a Clubman.