derestricting the old NS125R

[Robby]

I have an NS125R, the one before the NSR. Does anyone knmow how to derestrict it, or where to get a guide?
cheers
rob

[James]

The NS is just restricted by the exhaust. Fitting a K&N filter and re-jetting roperly will also give quite a bit of extra power.
looking back on all work i did to my bike, id probably just buy a micron exhaust for it and not bother. But if you're a bit tight and dont wanna splash any money out then ill tell you how to d-restrict exhaust.

Remove the exhaust competely from the bike. At the front of the exhaust where it joins the cylinder youll notice that the japs at honda have welded a smaller pipe into the exhaust. the later NSR's have spot welding on the restrictor but back when the NS was made they did the job properly. the pipe is welded solidly all the way round the exhaust. the easiest way to remove it is to hack saw around the exhaust flange(about 5mm deep)all the way round and the restrictor will just pull out.
There is another restrictor in the silencer. remove the silencer and youll see a steel plate inside. Find a way of drilling/smashing/melting through that and youll be able to see straight through the silencer. The bike is de-restricted. Have fun, try not to give too many grannys heart failure from the noise as well.

james