Early LI125 gearbox sprocket set up in a standard GP150 lump

[scooterslag]

Just building up another engine and I'm going to use a early LI125 box ( better option than the SX/GP 150 box's I've got) what would be the best sprocket set up for it? don't like the standard gearing on a SX/GP 150 lump, way too revy IMO. I'm sure people will say ' oh use this instead blah blah' but can't afford it at the mo and I know the early LI125 box has its uses. cheers Paul

[joespeed]

just fit it and try standard sprockets 15 x 46.very short first gear ok for two up shopping round a hilly town center!

[scooterslag]

just fit it and try standard sprockets 15 x 46.very short first gear ok for two up shopping round a hilly town center!

Hahaha, ideal for the hilly part of Devon I live in, want it to be a bit smoother as well so maybe a 47x 16 or would that be too much for a 150?

[sideout]

But the SX/GP 150 is designed to be revvy. That's why they put that gearbox in it. You might find it's down on performance if you move away from a 1:5.6 final ratio.

Once you get used to the gap between 3rd and 4th it's ok on a standard set up.

I use the early Li125 gearboxes on Mugello 186s with a clubman and a 17 front sprocket to give ~1:5.

[scooterslag]

But the SX/GP 150 is designed to be revvy. That's why they put that gearbox in it. You might find it's down on performance if you move away from a 1:5.6 final ratio.

Once you get used to the gap between 3rd and 4th it's ok on a standard set up.

I use the early Li125 gearboxes on Mugello 186s with a clubman and a 17 front sprocket to give ~1:5.

Yeah I know chap, been riding SX/GP150's for years, yep the 3rd to 4th is a pain, especially up hill, going to swap over to the LI box with standard 15x46 set up

[Stinky Finga]

li125 box and 17/46 sprockets works crackin on the muggy 186

[Toddy]

li125 box and 17/46 sprockets works crackin on the muggy 186

^agreed^

[sideout]

li125 box and 17/46 sprockets works crackin on the muggy 186

Dead right! .... when fitted with a clubman Standard GP200 gearing with a JL3

Yeah I know chap, been riding SX/GP150's for years, yep the 3rd to 4th is a pain, especially up hill, going to swap over to the LI box with standard 15x46 set up

Ideal! Just swap out the SX box for the Li125, then it will still be in the power in 4th as they have the same final ratios

[scooterslag]

li125 box and 17/46 sprockets works crackin on the muggy 186

Dead right! .... when fitted with a clubman Standard GP200 gearing with a JL3

Yeah I know chap, been riding SX/GP150's for years, yep the 3rd to 4th is a pain, especially up hill, going to swap over to the LI box with standard 15x46 set up

Ideal! Just swap out the SX box for the Li125, then it will still be in the power in 4th as they have the same final ratios

Indeedy hopefully the closer gap between 3rd and 4th should help with the hilly bits of my county cheers again Paul

[soullad]

I use the early Li125 gearboxes on Mugello 186s with a clubman and a 17 front sprocket to give ~1:5.

Good call.
these boxes are well made, relatively cheap and often had little use / wear.
Using this larger front sprocket to get the desired gearing is a preferred way, rather than fitting a different box, it helps with reducing stress on the clutch (think GP 18 x 47 to give 5.2 to cope with the inc. hp output), and this plus the short first gear ratio can only add to improved clutch life / general engine wear. Can also a new 81 link chain.