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Nihongo Hanaseruzo!
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Discussion Starter #1 (Edited)
Tell me about 2-strokes/Thinking about buying Honda NSR250R

I'm gonna be in Japan for a year next year, and over there 2-strokes are legal on the streets (unlike most places in the US).

The Honda NSR250 looks hot.



Only thing is, I've heard that 2-strokes need top-end rebuilds every once in a while.

So, first of all...what is a top-end rebuild? Second, how often do you have to do it? Third, would buying a used one be a good idea?

I'm also assuming a 2-stroke 250 is gonna make a good bit more power than a regular 250. Am I correct?

Hopefully somebody can cure my ignorance. Thanks!
 

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I don't know anything about the streetbikes, but I do know some about the 2 stroke dirtbikes.

All 2 strokes (that I'm aware of) will eventually need a top end sometime. How long between top ends? That varies wildly depending on the bike, and also how heavy your throttle hand is.

A basic top end rebuild consists of a new piston, rings, wristpin, circlips, maybe a new bearing, and the associated gaskets that would need replaced. Usually you buy it all in a set, then buy a gasket set. Dirtbike sets don't usually come w/ a new bearing.

I would bet a large sum of money that a 2 stroke 250 would eat a ninja 250 alive. Usually the 4 strokes have more top end, but the 2 strokes have much better accleration. In general, a 2 stroke cc's x2 is eqivalent to the 4 strokes cc's. IE- My KDX 200 is pretty well on par with an XR400 as far as power goes. Also, 2 strokes are lighter than 4's.

Downside? I'm guessing they have oil injection so you won't need to premix your fuel. That is a good thing, but just make sure you keep your oil reservoiur full.
 

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I agree with what josh said, lighter and about the equivalent of double its capacity.


I think that little muffler is funny



Looks like a honda seat from here... or is that part of the plastic on the fairing.... ahhhhhhh its just painted black to look like a seat!
 

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Kawpuke Extraordinare!
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An oil burner would be a neat bike to have for sure. However, I would look closely at what kind of driving your going to be doing. If its a lot of stop and go and slow speed driving, I would probably look at a 4 stroke. 2 strokes would probably load up and foul plugs goober up any kind of power valving they have. Also they arent going to have very much low end power like a 4 stroke would have. With that being said, probably hard to beat the fun factor when you get one out in the open and wound up.
 

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Compared to a 4 stroke, they have much different powerband characteristics. The 250 2-stokes weigh 120ish kg, and are rated at 45hp. That is however the restricted rating. Unrestricted is more like 60-65, and fully tuned will put them at 90ish. They potentially give 4-stoke 600 sportbikes a run for their money. They are very small, and the seat is also really really hard.
 

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Nihongo Hanaseruzo!
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Discussion Starter #7
Well that pretty much sums it up...thanks guys. :)

Gonna have to look around and see what my other options are. I guess I'll start leaning towards a ZXR250 or a nifty 250 motard. So many cool reasonably priced 250s in Japan...its amazing.
 

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Mexican Hard Shell Taco
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Stock 2 smoke 250cc won't eat alive a Ninja 250, will eat alive a 250 and a 500 together and stillfeel hungry for a ZX-6...


Fully tuned, with their low weight, they can run with the 600cc SS bikes, and do even better if you also get a better suspension and wheels.


They are nothing like the 250cc bikes you are used to, those are literaly race ready bikes, just get race plastics, remove the restrictors and that is it!

However, they are extremely manteinance hungry! More or less like a dirtbike, but if you run it hard, manteinance costs will go sky high.


Another interesting bikes are the 400cc that they sell at Japan, if you want to have fun with a 18,000rpm redline while pushing 60-70 hp from 400cc, get ready!
 

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Nihongo Hanaseruzo!
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Discussion Starter #9
Yup...but on anything over 250cc you have to pay the "shaken"...which is like a yearly car/bike ownership tax, and also involves paying for an inspection. Basically, it sucks. So, I'm planning to get a 250cc for sure.

400s are way cool though.
 

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ThePhorest said:
Yup...but on anything over 250cc you have to pay the "shaken"...which is like a yearly car/bike ownership tax, and also involves paying for an inspection. Basically, it sucks. So, I'm planning to get a 250cc for sure.

400s are way cool though.
You only have to get shaken every 2 years. Most bikes you buy will still have time left before their next inspection is due. If you are only going for one year, I wouldn't worry too much about shaken. There are some pretty nice machines in the 400cc class. (RVF400)
 

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I rebuilt a Yamaha 175 2-stroke when I was in HS replacing the piston, rings and main bearings. I would assume this is what is meant by top end rebuild. It's really not that difficult on a 2-stroke with no valves, valve train or cams to fool with.
 

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seems like everyone covered it pretty well. whoever you buy your smoker from, ask how many miles or hours you can put on the bike before a top end rebuild.

i looooooove my smokers :banana
 

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My first streetbikes were the older, 1970's models from Suzuki and Kawasaki. I had the GT380, 550, and kawi 750 two strokes, which were actually billed as touring bikes. Obviously back then they weighed a ton but they were faster than hell. Especially if you strip of the extra crap (like the oil injector and just pre-mix it). Finding a three into one was almost impossible in by the 1980's though.
Power delivery is harsh, like a dirtbike, but still fun. I used to slide the ass end around on them and have a blast. The triples suffered from the middle cylinder cooking off and I blew up several of them.
I've never had the fortune of owning a true two stroke sport bike though. I'd have one in a heartbeat though.
 

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Susser pretty much got it right, if you dont mind mauntaining it there the shit. It will SMOKE any 600 with a good pilot on them and do a good job on a 750 if the track is twisty enuf. The little 250's handle better than anything else ...

The old stuff solly speaks of was best forgotten.... evil nasty things they were :lol buy still loveable :leghump heh I still have one :)
 

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Nihongo Hanaseruzo!
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Discussion Starter #15
Sounds like it would be a blast for hitting the twisties...but cruising to class and around town might not be so hot. I know I'll be doing a lot of both, but I'll also probably be doing a good bit of touring...I wanna see the country by bike. So, sounds like a 4 stroke might be more up my alley.

Still...one-side swingarms, 2 cans, and lots of power...so sexy.
 

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Mexican Hard Shell Taco
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Powerwise they would do fine at the twisties and cruising. However, if you think that the ergos of a SS bike are a little bit extreme, the ergos of a 250cc will be a little bit more extreme ;)

Where I don't think a 2 smoke would do fine is in stop-go traffic. 2 Strokes are basically forced induction engines, and they need to rev up to have some power, low end is quite... weak, so you would end up eating clutches.

If you aren't going to be doing a lot of stop-go traffic or your commute won't involve stop-go a lot, you can be fine.



Ahh, if I only had $9000, there are still a few left over Aprilia RS250 in some dealerships here in Mexico City, lovely bike...
 
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