Why This 250cc Engine Have Long Lifecycle ? - Page 2 - Honda CBR250R Forum : Honda CBR 250 Forums
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post #11 of 18 Old 11-13-2017, 10:31 AM
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Speaking of KTM, I was pretty surprised to see the problems that Ari Henning of Motorcyclist magazine had with the RC390 he converted into a track-only bike a while back. How often do you see a blown head gasket on a fairly new modern motorcycle? And apparently it wasn't a one-off since other RC390 owners were complaining about similar problems with their bikes.
Supposedly KTM is addressing the issue, but considering how trouble-free most modern bikes are these days it's a reminder that poor design and manufacturing is still possible and the caveat about buying a 1st model year bike still has some validity to it even today.

https://www.motorcyclistonline.com/l...-gasket-repair
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post #12 of 18 Old 11-13-2017, 11:34 AM
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One of our UK mags did a long term review of the KTM390 a couple of years back and reported very poor corrosion resistance. They described the welding as having been done by 'someone who isn't a welder'.
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post #13 of 18 Old 11-13-2017, 11:39 AM
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Originally Posted by TrueFaith View Post
Speaking of KTM, I was pretty surprised to see the problems that Ari Henning of Motorcyclist magazine had with the RC390 he converted into a track-only bike a while back. How often do you see a blown head gasket on a fairly new modern motorcycle? And apparently it wasn't a one-off since other RC390 owners were complaining about similar problems with their bikes.
Supposedly KTM is addressing the issue, but considering how trouble-free most modern bikes are these days it's a reminder that poor design and manufacturing is still possible and the caveat about buying a 1st model year bike still has some validity to it even today.

https://www.motorcyclistonline.com/l...-gasket-repair
I've ridden a RC390 a bit, and the one I've ridden is on its second engine. The first blew a cam chain with a KTM service tech aboard during a test ride to sort an nagging issue with shutting-off and not restarting when hot.

KTM did replace the engine for free and included the required maintenance that had already been done.

I found the RC engine to be too dull for me, though the chassis and handling were excellent. As soon as the corners started you forgot about the engine.
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post #14 of 18 Old 11-13-2017, 12:18 PM
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About ten years ago, when motocross switched from using 250 two strokes to 450 four stroke motors I was hoping that some of that technology would be used to create a lightweight, road going single with 40-50bhp. so far only KTM have shown any inclination to go down that route.
No doubt the current crop of 450cc four stroke motocross engines are a testament to the kind of power & performance can be achieved from a mid sized single cylinder. However, those engines are not built to withstand sustained operation over time at higher RPM's, which is a primary consideration for a road going bike. They are very "high strung" purpose built motors, where motocross & supercross tracks rarely demand more than 5 to 10 seconds of WOT over the longest straights before a rider is backing off for a tight corner, or when in mid-air over a big jump.

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post #15 of 18 Old 11-13-2017, 06:08 PM
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No doubt the current crop of 450cc four stroke motocross engines are a testament to the kind of power & performance can be achieved from a mid sized single cylinder. However, those engines are not built to withstand sustained operation over time at higher RPM's, which is a primary consideration for a road going bike. They are very "high strung" purpose built motors, where motocross & supercross tracks rarely demand more than 5 to 10 seconds of WOT over the longest straights before a rider is backing off for a tight corner, or when in mid-air over a big jump.
I'd still have thought they could be detuned/refined/developed into 40-50bhp units with the required durability for road use. KTM and Ducati's big twins make well over 100bhp per litre from similar or larger cylinders.
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post #16 of 18 Old 11-14-2017, 06:48 PM
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One of our UK mags did a long term review of the KTM390 a couple of years back and reported very poor corrosion resistance. They described the welding as having been done by 'someone who isn't a welder'.
KTM needs to improve it's quality control. Stuff like that mustn't happen. Maybe it wasn't a good idea to outsource to India.

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post #17 of 18 Old 11-21-2017, 10:24 PM Thread Starter
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KTM needs to improve it's quality control. Stuff like that mustn't happen. Maybe it wasn't a good idea to outsource to India.
BMW outsourced to India also for their G310. :/
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post #18 of 18 Old 07-12-2018, 05:13 AM
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I eyed off the ktm390 before I bought the CBR and the local research showed way to many problems and 3 for sale with blown low mileage motors over a couple of months.That sort of rubbish will kill a bikes reputation quick fast.
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