ChinaRiders Forums - View Single Post - RX3 performance mods? Horsepower upgrade potential?

Thunder · 02-06-2018, 12:40 PM

I believe that there is a big bore kit out there.
Look on the dual sport section of this forum for Chonda's posts in the pitster pro LXR.
I think it's a 82mm big bore cylinder and piston. Around 283cc's, but it's called the NC300 kit.

The cylinder head and ports on this engine are actually quite good as they are, I don't think you would get any noticeable gain with port work, in fact, I'm fairly certain port work would hurt low speed and mid-range torque.

The intake and exhaust systems are not exactly restrictive either.

It's a 250cc engine pumping out 24.8hp, that's really quite pretty good!

Compare that to the:
CRF250L @19.6hp
KLX250 @19.5
Xt250 @17hp
Wr250@ 24.8hp.

The numbers don't tell the whole story of course, the important part is the useful power available during normal riding conditions, (the area under the curve)but it does show that the NC250 is right in the ball bark with any of the "major players".

Like any engine, I think that you can extract more power from the NC250 engine.
However, at some point I think reliability and durability may decline.

If it is strictly a play bike, like the Pitster pro LXR, then I think you can get away with it.
If you need the bike to get you out to the trails and then back home again, then I'd leave it alone.

That being said, a big bore kit shouldn't effect reliabilty if it is a good quality kit.
YRMV!

If you like the bike, buy it for what it is, not what it could be.
(I might catch hell for that line!)

02-06-2018, 12:40 PM	#7
Thunder Join Date: Aug 2016 Posts: 24	I believe that there is a big bore kit out there. Look on the dual sport section of this forum for Chonda's posts in the pitster pro LXR. I think it's a 82mm big bore cylinder and piston. Around 283cc's, but it's called the NC300 kit. The cylinder head and ports on this engine are actually quite good as they are, I don't think you would get any noticeable gain with port work, in fact, I'm fairly certain port work would hurt low speed and mid-range torque. The intake and exhaust systems are not exactly restrictive either. It's a 250cc engine pumping out 24.8hp, that's really quite pretty good! Compare that to the: CRF250L @19.6hp KLX250 @19.5 Xt250 @17hp Wr250@ 24.8hp. The numbers don't tell the whole story of course, the important part is the useful power available during normal riding conditions, (the area under the curve)but it does show that the NC250 is right in the ball bark with any of the "major players". Like any engine, I think that you can extract more power from the NC250 engine. However, at some point I think reliability and durability may decline. If it is strictly a play bike, like the Pitster pro LXR, then I think you can get away with it. If you need the bike to get you out to the trails and then back home again, then I'd leave it alone. That being said, a big bore kit shouldn't effect reliabilty if it is a good quality kit. YRMV! If you like the bike, buy it for what it is, not what it could be. (I might catch hell for that line!) Last edited by Thunder; 02-06-2018 at 03:19 PM.
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