how do you derestrict a yamaha ybr 125?

Question

how can i make the ybr 125 go faster improve performance will a different exhaust do much good ,can some one hellp me clive

Answer 1

It's not restricted. 65-70mph is the maximum speed it can go.



125cc 2 strokes are the ones that are restricted. Yours is a 4 stroke.



Exhaust system will do nothing apart from sound, you might gain a little better throttle response but that's it. I had one on my Honda XLR125, did nothing for acceleration or top end - It was also a 4 stroke.



Easiest & cheapest thing to do is change the front sprocket. Less teeth will improve acceleration but sacrifice a little top end. Then adding more teeth will improve top end but sacrifice a little acceleration. If you do decide to go that method, -2 or + 2 teeth is OK personally.

Answer 2

I laugh when this question comes up, amazing how many wet necks think that a 125cc will all of a sudden release such power once you change a few things.



It's a 125cc, nothing will happen apart from a difference from an extra 10mph MAX if your lucky.



It's a 125cc it's not got a 600cc hidden in there somewhere, dream on.

Answer 3

Not a lot you can do, the current crop of 125s are designed down to the restrictions, you'd have to spend a lot of money swapping engine internals, ECU, exhaust etc.



Instead, put the money towards getting your full bike licence, then sell the 125 (they're easy to sell, hold their price because learners want them) and get a used 400 or 600, much nicer to ride, 'cooler' and with a full licence you can give cute girls rides...

Answer 4

No the exhaust will make little difference and even doing that will void your insurance. There is little to be done to derestrict it as it is naturally restricted by its design

Answer 5

Try disconecting and unsrewing engine temperature sensor from cylinder head,reconect sensor and tape securly away from engine heat, this will trick ecu that engine is running cold and supply a richer fuel ratio.

Answer 6

Go do a PX for a 500!

Answer 7

any alterations would make minimal gains