hi,
i have a yamaha r125 a does any1 know if a leo vince exhaust will give me a good upgrade on power or is it not worth it
many thanks
scampi 
It’s not worth it. Also if you are on a CBT you are limited to 14.8bhp, and if you modify the bike to go beyond that you are then not licensed to ride the bike nor will your insurance cover you.
I had a look at changing the can when I was on a 125. The cost involved doesn’t make it worth it, when the gains are so little.
well end of that day its completely up to you itll look alot better and sound better than the standard one no doubt you will get some power increase have a look on their web site and see if theres any stats
and about going over the 14bhp no one is going to be able to tell if you are or not unless your clocking up stupid speeds on it
its your bike enjoy it and do what you want it to aslong as your happy
Medium length answer = yes, Leo Vince make the best sounding pipes 
Long answer = it depends how long you intend to keep the bike. Like Kevsta says, it wouldn’t be worth it if you’re just using the bike to gain some experience before you do your test and sell it to buy something bigger.
I don’t know how much the can is, but in this case, it’s probably not worth spending too much money on a 125.
Some people do keep these 125s though even when they pass a test though…Plus points…They look cool, and they are very economical to run.
Save your money.
Buy a second hand slip on if you want a sweeter tune played from the back - then spend spend spend after your test
hi,
im gunna keep her even when i pass my test im thinking of doing her up so i can take her to track days to practise on, coz i intend to buy a yzf r125 at race spec and start racing, but im gunna get sum pactice in first,
this is my bike with the exhaust attached she looks awsome
many thanks
scampi
Goodluck to you mate 
They’re great looking bikes and I’m pretty sure you’ll get decent money for it when you do sell it.
Nice idea using it on track…Stick decent tyres on it and I can imagine it will handle brilliantly.
my gamma has a micron pipe power pipe and gave it a load more power in the hi range but thats a 2t and was restircted so thats prob why…
What series would you race it in? The only place i’ve seen these raced is in a one make series in Italy.
It will never be competitive against purpose built 2 stroke 125GP bikes.
the pipe is worth it for the sound, not for performance. i have a race system fitted to my CBR125R and it is LOUD on a whole new front, but no real performance gains.
If you find one second hand [got mine on eBay fo £100] that would be your best bet!