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70 HP / less than 300 lbs?

17177 Views 47 Replies 29 Participants Last post by  pplassm
Bring it on Aprilia!
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Not with this motor

MX 4 stroke motors installed in sport/race bikes are problematic at best.

Dry oil sump, wide gearbox ratios, compact cases, cause stresses and issues that don't come up in the dirt.

The concept is sound, but it will need a redesign before it hits the street / track.

Now about putting that bored and stroked DR-Z400 motor in my RGV chassis....
Ummmm, the death of two-stroke offroad (and street) motorcycles is most definitely not the result of consumer choice. It is plain and simple govt mandate.

I'd take a two-stroke powerplant for any kind of performance riding over a four-stroke. Four-strokes make better tourers (unless you fit 10 gallon tanks to two strokes) or cruisers, but for sportbiking or dirtriding two-strokes are immeasurably superior. They would dominate still today if they could meet pollution mandates.
That would make a hell-uv-a flat-track motor! Does it sound cool?
Ironic isn't it? Talk about things going full-circle.

First you had the two-stroke single replacing four stroke twins in off-road racing and riding.

Then the two stroke ruled the Earth for a while, only to be replaced by the four stroke single.

And now back to four stroke twins for off-road racing and riding.

What's next? Porridge pot helmets & Uvex goggles? Leading link forks?

Seriously though, I was watching MX on the tube the other night and noticed there were almost no 2 strokes in the 250 class.

We had to expect that, since it was only a matter of time until the factories got the technology sorted out, and 4 stokes started kicking some a$$ (without blowing up, that is).

And to top it off, my buddy who rides a KX500 is selling it and buying a new CRF450X. (I'll keep my CR500 for a few more years, thank you)

The 2 stroke is dead! Long live the 2 stroke!

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I'm still jonesing for an RD400 but I'll take a few deep breaths and let it pass.
I agree somewhat, but technology is making leaps and bounds in the 4 stroke off-road game.

Lighter engine components mean more power and quicker revving. Better designs lessen reliability and maintenance issues.

And as you can see in the 250 class nowadays, hardly anyone rides a 2 stroke.

And then you have the safety nazis and environmental kooks who hate the 2 stroke for what it is, noisy and dirty. Let's face it, the two-stroke dirt bike is on the ropes, goin' down for the 10 count.

Hey, what ever happened to the Orbital 2 stroke engine design, that combined 2 and four stroke technologies? That seemed a good compromise between power and the environment (two stroke top end, four stroke lower end).

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I think that this bike is cool as heck, and will be a relative failure in the U.S. Without a tiered licensing structure basically mandating the purchase of low-power / small-displacement bikes, a bike like this doesn't make economic sense for most U.S. consumers.

A 600cc-ish supersport offers more performance and will continue to provide thrills, chills and probably spills too for a wider range of riders in number and for individual riders over a longer time.

Note that I'm not endorsing supersports as fundamentally "better" than this concept - outside of racing there's too much variety for that word to have much meaning in most motorcycle discussions - I'm just saying that, in the U.S., it will never really take off.

That being said, I hope against reason that they sell enough so that I can see one in person.

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Hey. I went snowmobiling last weekend and on the way home in my truck we almost hit a Golden Eagle that was eating some road kill! Two bad I wasn't on a Harley, eh?
You know what else is ironic? The announcement of this motor isn't met by an avalanche of catcalls from MOrons about how inferior it is because it doesn't have 100+ hp. I was beginning to believe that 100HP was the minimum acceptance level for a motorcycle.
I know, I was beginning to develop "horsepower envy."

Check out this link:

It might be a 2 stroke without lower-end scavenging. Wave of the future?
Well if it's on some dork's blog it has to be true, right?
It puts out about 42HP and 59 Ft-lbs. Way below the minimum necessary to be cool. But it gets an estimated 80 mpg in a light car. Not bad. Imagine the mileage on a motorcycle. 100+? A gas engine would be faster but you could go 500 miles between fill ups. In an off road bike you'd never worry about running out!

How many gas engines can run 250 hours at full output?

Diesel performance is a bit strange compared to gas since they get less HP but loads of torque.
Heh heh. I bought a new two-stroke snowmobile this year so I can avoid the coming mandate that will force people on overweight four-stroke machines. As much as I use one (maybe 200 miles a year) it'll last me 20 forever.

I might just make a point of picking up a couple more two-stroke dirt bikes to keep in reserve just so that I can have the pleasure of pi$$ing off the enviro-nazis for years to come.
Good for you! Fight the urge to four sickle. All that un-needed nonsense spinning around, whirring and clanking about! Bah, who needs it?

Let's see, how many two strokes in my "reserve"? Hmmm..

1971 DT1MX Yamaha 250

1972 DT250 Yamaha Enduro

1973 TM250 Suzuki Champion

1976 TC100 Suzuki (8 speed)

1987 CR500R Honda (ported for top-end!)

And then there's a...

1953 Clinton 3hp Lawnmower (Blooey pipe, the neighbors hate me)

1982 Shindawa Edge Trimmer

1948 Elgin 8hp Outboard

1955 Martin 6hp Outboard

(BTW Sold the RD400 for big$$$. Hah, they'll be sorry.)

Not to mention engine parts, engines in boxes, in cleaning dip, buckets, and various degrees of disassembly (Model engines, weed wackers, chain saws, etc..etc..).

Of course there are no cars in the garage, but that's the way it should be...

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put it in a supermoto

Please, please put it in a supermoto. My wallet is ready to open. Who will be the first to bring a freshly designed supermoto to market. A 500cc or so motor should do it.
Just got my buddies '69 YAS-1 RD purring like a kitten this weekend. Luckily I didnt see my reflection as I was riding it around the neighborhood, probably would of crashed laughing so hard. 6'6 280 on a tiny 125 2 cyl smoker is a sight to behold. But the little engine that could still had pretty good get up and go, I'm impressed. Now I dont want to give it back, then again my neighbors will probably be happy when I do.
In keep with the theme it would have had to be a Screaming Eagle version.
A friend of mine had one of those! He piped, ported and put high compression pistons in it. It probably got about 17-18 HP. It had a powerband that was about 2000 rpm wide. But it really screamed (literally) for a 125 at the time. I rode it a couple of times, but got tired of people flipping me off and shaking their fists.
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