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Discussion Starter #1
So Honda right now have CB300R, CRF250L, Rebel 250, CBR250R/CBR300R. All these bike use similar engine.

It makes me wonder. What makes this engine special that Honda decided to use these engine on their many bikes ?

Reliability ? Proven ? Simple maintenance ? Does this mean this engine will have long lifecycle ?

Thoughts ?
 

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Honda's small motorcycles have a reputation for long engine life provided that the maintenance schedule is followed. Adjusting valves and changing oil and filter are important. This engine uses shims for tappet adjustment so the intervals are longer but the checks need to be done and shims changed as needed for generous clearance.
 

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Long lifecycle is the way the motorcycle market is now.
In years gone by, constant development of new technology to gain more power was essential to drive sales in all sizes of bikes. Now that is reserved for the big flagship models and economy (both in the engines themselves and in their manufacture) is more of a priority for smaller models.
Bike manufacturers are now turning more to different styling variations on a common basic platform to generate sales. Yamaha's FZ/MT series and Triumph's twins are good examples of this.
Also, the European market has a maximum power to weight ratio for some categories of riding licence which means that a relatively simple motor is all that is needed.
 

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So Honda right now have CB300R, CRF250L, Rebel 250, CBR250R/CBR300R. All these bike use similar engine.
The Rebel 250 engine is not the same engine as used in these other bikes. It's a much older design. The new Rebel 300 shares the same motor as used in the CBR300R & CB300F.

... It makes me wonder. What makes this engine special that Honda decided to use these engine on their many bikes?

Reliability ? Proven ? Simple maintenance ? Does this mean this engine will have long lifecycle ?

Thoughts ?
From Honda's standpoint, it makes financial sense to use the 250/286 motor in a number of different models. Increased production volume is the way to recover initial R&D and tooling costs. Which in turn allows Honda to keep the retail price point of these bikes low.
 

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Also, the European market has a maximum power to weight ratio for some categories of riding licence which means that a relatively simple motor is all that is needed.
While that is so the max HP for those licenses would be 48, so the 26hp 250cc and the 31hp 286cc don't cut it. That's what the 500 series was designed for. That's also the reason why you rarely see the 250/300 models in Germany. They just don't fit into any license category and people often go for bigger = better.
 

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While that is so the max HP for those licenses would be 48, so the 26hp 250cc and the 31hp 286cc don't cut it. That's what the 500 series was designed for. That's also the reason why you rarely see the 250/300 models in Germany. They just don't fit into any license category and people often go for bigger = better.
True. I haven't done the sums but the CBR250/300 would have to be a lot lighter than they are to fall foul of the power to weight restriction.

Regarding whether or not the 250 motor is 'special', I'd say 'not special'. If Honda can get 160HP or more out of a CBR1000 which is 4 250cc cylinders they should be able to get 40 out of a single 250 and make a bike that would perform as well or better than the 4 cylinder 250s from the 80s and 90s. They'd only do that if they thought they could attract enough buyers to justify the much higher price they would have to charge.
 

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From Honda's standpoint, it makes financial sense to use the 250/286 motor in a number of different models. Increased production volume is the way to recover initial R&D and tooling costs. Which in turn allows Honda to keep the retail price point of these bikes low.
^ This.

Honda has a good product, but so do most of the major players at this point. Honda has made major engine mistakes in the past, like oiling/cam problems on the early Interceptor 500s. Some CBR250Rs have had unusual engine problems as well.

At this point, especially with their smaller/less expensive engines, they want to get the best bang for their engineering and production buck.
 

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True. I haven't done the sums but the CBR250/300 would have to be a lot lighter than they are to fall foul of the power to weight restriction.
Wouldn't they need to be above the 48HP restriction for the whole power to weight thing to take effect. IIRC that only applies to bikes that are more powerful but get restricted to 48HP.

If Honda can get 160HP or more out of a CBR1000 which is 4 250cc cylinders they should be able to get 40 out of a single 250 and make a bike that would perform as well or better than the 4 cylinder 250s from the 80s and 90s
I believe there are some Asian countries that still have a 27 HP license. Our CBR's 26.4 HP would make sense for that and explain why the power is so low.
 

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Discussion Starter #9
True. I haven't done the sums but the CBR250/300 would have to be a lot lighter than they are to fall foul of the power to weight restriction.

Regarding whether or not the 250 motor is 'special', I'd say 'not special'. If Honda can get 160HP or more out of a CBR1000 which is 4 250cc cylinders they should be able to get 40 out of a single 250 and make a bike that would perform as well or better than the 4 cylinder 250s from the 80s and 90s. They'd only do that if they thought they could attract enough buyers to justify the much higher price they would have to charge.
Well, Honda made CBR250RR. As far as i know, this bike right now only sold on Indonesia and Japan. Now news whether this bike will be sold in other countries. And in Japan, this bike is more expensive than CBR400R.

I think if Honda gonna sell it on other countries, they must stroke up the engine to 350cc or something. To compete with Ninja 400, R3, RC390, etc. Eventhough this bike gonna compete with their CBR5000R too.
 

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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.
 

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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/long-term-ktm-rc390-blown-head-gasket-repair
 

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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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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/long-term-ktm-rc390-blown-head-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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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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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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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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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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