Need a bigger engine for lsm 125

[Diggs]

Hi everyone I've got a lsm 125 (lexmoto) I've had it for nearly a year and find it a decent bike overall other than a few mods which I recommend all new lsm owners do (upgrade chain/change tyres). I now find myself needing more power/speed does anyone know of an engine I can replace my present 1 with (ybr copy).
Thanks for any help Diggs

[culcune]

Isn't there a 250cc YBR?

[Diggs]

Isn't there a 250cc YBR?

There is but I've not been able to find one for sale

[Kennon]

YBR 250's are quite rare to come across in the UK, you can fit a big bore kit to the YBR engine.

Kennon

[Zorge]

I guess you're looking for bolt-on solution, but if you're not constrained with it, and have ways to modify the engine mounts and some other nick nacks, virtually, the only limit are the dimensions of a engine.

[Diggs]

YBR 250's are quite rare to come across in the UK, you can fit a big bore kit to the YBR engine.

Kennon

I would do that but part of the problem is I run out of gear on top end the revs are willing but the gearbox isn't

[Kennon]

Change the sprockets for a smaller rear for more topend but you don't want to sacrifice the bottom end too much when I had my 125 supermoto it was pumping out 20bhp it would top out at 73 originally but was a hoon in the city doing long distances i geared her up to do 86mph and drop a tooth from the front to keep some of the low down grunt.

Kennon