Well I would have thought the first thing would be change the exhaust...

Dont know if anyone does a performance exhaust for the NX250, so you might have to get a different can and mod the mountings a bit.

Open up the airbox a bit, and upjet if required.

After that...I dont know...I dont think your going to get much from a 26hp 250 single...

 

have you tried looking into the CBX250 RS that had a rfvc 250 engine
it had 2 carbs on it and turned out summat like 33 bhp i think
merv

 

I dont think that will work...

The NX250 afaik is a liquid cooled engine that wasnt used in much if anything else...the only way I think you will increase the power beyond what has already been mentioned is try and get a big carb and set that up...

Unless you can get a big bore kit for the engine...

 

The NX250 is quite a nice bike for its size.
But the market is not flowing with "Go fast" parts for it.

However a less restrictive silencer/End can, combined with an adjustment of the carb jettings, could very well produce a few extra horsies

In fact, I would assume the NX250 would respond to the same changes as the larger capacity RFVC engined Hondas.

Edit: Praise the Man!

Honda have OEM parts for tuning!

Honda had a special model called AX-1
Just get your local Honda dealer to supply you with the
camshaft and carb jets from the AX-1
3 additional HP

>Another version of Honda NX-250 was Honda AX-1. Using the same chassis as the NX-250, came standard with alloy rims, aluminum Pro-Link rear suspension and dual round headlights, different camshafts and carburetor settings. AX-1 outputs 29 HP at 8500 RPM at 11 to 1 CR and 2,4 Kgm torque at 7500rpm.<

 

The NX250 is quite a nice bike for its size.
But the market is not flowing with "Go fast" parts for it.

However a less restrictive silencer/End can, combined with an adjustment of the carb jettings, could very well produce a few extra horsies

In fact, I would assume the NX250 would respond to the same changes as the larger capacity RFVC engined Hondas.

Edit: Praise the Man!

Honda have OEM parts for tuning!

Honda had a special model called AX-1
Just get your local Honda dealer to supply you with the
camshaft and carb jets from the AX-1
3 additional HP

>Another version of Honda NX-250 was Honda AX-1. Using the same chassis as the NX-250, came standard with alloy rims, aluminum Pro-Link rear suspension and dual round headlights, different camshafts and carburetor settings. AX-1 outputs 29 HP at 8500 RPM at 11 to 1 CR and 2,4 Kgm torque at 7500rpm.<

I have looked and looked into this. Cams for NX and AX have same part number. The specs show AX-1 has less hp.

 

Good find there!

Order the camshafts and carb jets as Kjell said,
and then get an end can from some other bike and modify it...

Maybe a sports can for the NX650 would fit (might need to be cut down though)

 

Well i have rebuild my ... to the max , as I like to say

But I got just the best parts for it , but i did not hack it

About the exhaust , i got the most expensive one from Marving .

More info here .. JULY 07

 

Hi there..

I was surching for a power upgrade for my NX when I Googled this topic.

Placing the cam of a AX-1 in a NX is written on more internet site's.
But has someone over here tried it?
What was the diferance, dyno print perhaps?

 

upgrade your spark plug (iridium)
Rejet your carburetor
Upgrade your exhaust system