High Mileage NC250 engines?

GlennR · 01-17-2022, 09:54 PM

I'm curious how long these engines have been lasting & figured this would be the best place to ask. What kind of miles have you guys been putting on your bikes? Have any of you needed to replace the piston yet? Will they run 50,000 miles on a piston?

I've got a bike that uses the same engine, but I figure the RX3 is much more popular and is designed for touring.

Huck369 · 01-18-2022, 07:18 AM

Got 15,000+ miles on mine....did put a 300cc kit in it, but not because it needed it, just because I wanted too...

lilgman · 01-18-2022, 07:57 AM

SpudRider had to do a top end at 22,450 miles because of defective valves. He reports adequate cross-hatching in the cylinder, but did replace rings while it was apart. The bike went on to 27,250 miles without further problems. Seems like the last he posted on this forum was 2017. Seems like I read about some other Rx3s that had more than this, but I can't seem to find it now. Looking forward to more answers on this!

Here's SpudRider's thread which has a lot of really good info on a top end rebuild.

https://chinariders.net/showthread.php?t=18895

edit: I think he suspected defective valve seats, not valves

GlennR · 01-18-2022, 11:38 AM

Quote:

Originally Posted by lilgman

SpudRider had to do a top end at 22,450 miles because of defective valves. He reports adequate cross-hatching in the cylinder, but did replace rings while it was apart. The bike went on to 27,250 miles without further problems. Seems like the last he posted on this forum was 2017. Seems like I read about some other Rx3s that had more than this, but I can't seem to find it now. Looking forward to more answers on this!

Here's SpudRider's thread which has a lot of really good info on a top end rebuild.

https://chinariders.net/showthread.php?t=18895

I miss SpudRider. He was a great contributor.

It's been quite a while since his posts, so I figured maybe other folks had been loading up the miles since then. I'm surprised that we haven't seen a RTW, for even a cross-country ride report yet. Maybe I just missed them?

I've been impressed with the NC250 in my bike. The only problems I've had have been with the EFI & the loud exhaust, neither of which are actually part of the engine.

pyoungbl · 01-18-2022, 03:20 PM

I seem to recall Joe Gresh's friend Sergeant Zuo having over 50K miles on his RX3. I have no doubt that there are lots of high mileage RX3 bikes in China, we just do not hear much about riding in that part of the world.

RE the loud exhaust....on the RX3 a lot of that noise is actually intake noise, not exhaust. You can try an experiment. Ride at a steady 55 or 60 mph (faster is even better) and modulate the throttle. The engine speed won't change much but you will notice an immediate change in noise level since you have opened up the throttle body. I am convinced the change is due to resonance at the intake.

01-17-2022, 09:54 PM	#1
GlennR Join Date: Oct 2013 Location: Boone, NC Posts: 187	High Mileage NC250 engines? I'm curious how long these engines have been lasting & figured this would be the best place to ask. What kind of miles have you guys been putting on your bikes? Have any of you needed to replace the piston yet? Will they run 50,000 miles on a piston? I've got a bike that uses the same engine, but I figure the RX3 is much more popular and is designed for touring.
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01-18-2022, 07:18 AM	#2
Huck369 Join Date: Apr 2008 Location: Somerset, KY Posts: 684	Got 15,000+ miles on mine....did put a 300cc kit in it, but not because it needed it, just because I wanted too... __________________ Huck 2013 Honda NC700X 2013 Moto Guzzi V7 Stone 2016 AJP PR4 2022 Templar X 250 2021 Sondors Metacycle AMA Life Member
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01-18-2022, 07:57 AM	#3
lilgman Join Date: Jan 2020 Location: Lesotho Posts: 105	SpudRider had to do a top end at 22,450 miles because of defective valves. He reports adequate cross-hatching in the cylinder, but did replace rings while it was apart. The bike went on to 27,250 miles without further problems. Seems like the last he posted on this forum was 2017. Seems like I read about some other Rx3s that had more than this, but I can't seem to find it now. Looking forward to more answers on this! Here's SpudRider's thread which has a lot of really good info on a top end rebuild. https://chinariders.net/showthread.php?t=18895 edit: I think he suspected defective valve seats, not valves Last edited by lilgman; 01-19-2022 at 02:49 PM.
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01-18-2022, 03:20 PM	#5
pyoungbl Join Date: Feb 2016 Location: Portsmouth, Virginia, USA Posts: 632	I seem to recall Joe Gresh's friend Sergeant Zuo having over 50K miles on his RX3. I have no doubt that there are lots of high mileage RX3 bikes in China, we just do not hear much about riding in that part of the world. RE the loud exhaust....on the RX3 a lot of that noise is actually intake noise, not exhaust. You can try an experiment. Ride at a steady 55 or 60 mph (faster is even better) and modulate the throttle. The engine speed won't change much but you will notice an immediate change in noise level since you have opened up the throttle body. I am convinced the change is due to resonance at the intake.
	2