[eng] Hello, possible new owner here.

[Kivi]

Hi! Thank you for this great website.
I am thinking to buy NX250. Seller says it is from 1993 year and has 17KW. I have driven it and it seems like it is restricted, but in the papers it says 17KW.
It is MD25-310050X, engine:MD25E-310051X.
Can you help me with these numbers and can the engine be de-restricted easily, so to be back at full power?
This the ad for the bike I think to buy or not:
https://www.polovniautomobili.com/motor ... tor-nx-250

Thanks.

[scrambler]

Hi there,

Welcome to the board - where you from ? According to the frame number this particular NX was built in 1990 for the German market as a restricted 12,5kw version. If the registration document says that it was de-restricted I am pretty positive that it was really de-restricted. Because it would not make sense to spend all that money on the paper work without actually having more horse power. (the other way around happened a lot: many owners de-restricted their NX without having that written into the registration document because that costs, too) .

The 12,5kw intake manifold has a marking on the right side, nothing is written there on the 17kw version.

If that NX lacks power it may have three reasons.
1. You did not crank up the engine enough. The only way for a decent acceleration is to rev the engine up to at least 8000 (!) rpm. If you shift too early you need a lot of patience. If you rev like hell you should reach 120 km/h in relatively short time.
2. The carburettor, the air filter or the muffler is clocked up and need cleaning/replacing.
3. Some NX250 are noticeable lamer than others – there is nothing one can do about it.

manifold NX250 12_5.jpg

[Kivi]

I am from Serbia, and the bike was imported from Germany in 2007. I currently drive a chinese 200cc 4t pushrod enduro bike.
Thanks for the answers - I really have not twisted the throttle all the way to 8-9000rpm, maybe I would need some time to get used to the bike, if I buy it. But I have only tested the bike for 1km, because it is not registered at the moment.
My Chinese bike has 9KW-13hp, and when I tested the NX, it did not seem like almost 100% more powerful (17kw), it seemed only little more powerful, so I got a feeling that it might have 12.5kw power. But, I used to my pushrod bike, witch has torque at the low rpm and does not like the high rpm, so it is very possible that I did not know how to properly drive the bike - to twist the throttle more. If I buy it, I will get used to it very quickly. For me it would be most important to have the possibility to de-restrict it, if, in any case, it is restricted right now (I do not really 100% believe in serbian papers).
The owner said that the bike can go upto 125kmh and then stops. Chain and sprockets are bad.
The bike has very corroded exhaust muffler. Owner tried to repair it, it was done bad, now it is free-flowing and VERY loud and, from expiriance, I know that this could also be cause for less power.
The owner has not really driven the bike much for the last 13years. He also did not do much maintence, so the air filter and carburator might be bad. Other than that, bike started good at the smallest push of the button, and engine sounded good.

Thanks for answers, and thanks for writing in foreign language I now see the Interntional riders forum here

[scrambler]

He also did not do much maintence, so the air filter and carburator might be bad. Other than that, bike started good at the smallest push of the button, and engine sounded good.

Ok, the latter is the most important issue. Even though the NX250 engine is very durable you never know what previous owners did (or not did like checking the oil level). But one thing you have to be aware: NX250 parts are rare and hard to find, the muffler for instance. If you can welt you could modify a muffler from another bike – given that there is no TüV like organisation in Serbia. Around here it is very difficult to get another muffler legalized.
Wear parts like sprockets and cables are available as aftermarket parts and with a carb cleaning and new air filter the bike should run much better. As said, due to the motor characteristics the fun with the NX250 begins above 8000 upm, more like a two-stroke than a thumper. Some don’t like it but I love it

[Zigomatix]

Hi Kivi,
I started a topic about muffler on the international part of the forum. You should have a look at it.
I also uploaded pictures of parts available from a guy in France if needed.
See you

Patrick