2 stroke vs 4 stroke HP

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7/22/2020 5:42 AM

Why do 4 strokes have higher HP rating when a 2 stroke of half the displacement is comparable in speed?

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7/22/2020 5:44 AM

They aren’t comparable in speed.
Not any more

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7/22/2020 5:49 AM

Joel Spoor wrote:

They aren’t comparable in speed.
Not any more

Two different worlds.

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rarararaataatatatata

7/22/2020 7:35 AM

Well then why haven't the rules been changed? Cough... sarcasm...dead horse

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7/22/2020 8:19 AM

Photo
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7/22/2020 8:25 AM

mikec265 wrote:

Well then why haven't the rules been changed? Cough... sarcasm...dead horse

They did, 250 2 strokes now run in mx2 class.

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rarararaataatatatata

7/22/2020 10:32 AM
Edited Date/Time: 7/22/2020 10:33 AM

mikec265 wrote:

Well then why haven't the rules been changed? Cough... sarcasm...dead horse

MZ193 wrote:

They did, 250 2 strokes now run in mx2 class.

Not in the US at least not on the pro level

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Ride like a girl!!!
2016 KTM 500 EXC-F
Current project: 2007 Kawasaki KX250-R7 retro build
Current project #2: 1987 Kawasaki KX250-E1 rider/racer resto
1989 KX125 resto
1987 RM250 resto

7/22/2020 10:35 AM

queen of spodes wrote:

Not in the US at least not on the pro level

Pro's wouldn't race 2 strokes anyway, at least anyone who is fast enough to win.

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7/22/2020 10:38 AM

Timo_2824 wrote:

Pro's wouldn't race 2 strokes anyway, at least anyone who is fast enough to win.

via GIPHY

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7/22/2020 10:51 AM
Edited Date/Time: 7/22/2020 3:54 PM

Timo_2824 wrote:

Pro's wouldn't race 2 strokes anyway, at least anyone who is fast enough to win.

Canada but still:

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Ride like a girl!!!
2016 KTM 500 EXC-F
Current project: 2007 Kawasaki KX250-R7 retro build
Current project #2: 1987 Kawasaki KX250-E1 rider/racer resto
1989 KX125 resto
1987 RM250 resto

7/22/2020 10:59 AM

queen of spodes wrote:

Not in the US at least not on the pro level

Which is a fucking joke. DC's response to this questions in a prior Vital thread was weak sauce. Basically it's OEM pandering.

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7/22/2020 11:09 AM

Not nearly as bad as whining about MUH 2 STORKES in 2020

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7/22/2020 11:13 AM
Edited Date/Time: 7/22/2020 11:18 AM

MZ193 wrote:

They did, 250 2 strokes now run in mx2 class.

queen of spodes wrote:

Not in the US at least not on the pro level

Timo_2824 wrote:

Pro's wouldn't race 2 strokes anyway, at least anyone who is fast enough to win.

Even if that was true, I'm not sure why "fast enough to win" should matter in the least bit, anyways. There's an entire field of riders who have to decide what bike they will ride, not just three or four.

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7/22/2020 11:13 AM

MZ193 wrote:

They did, 250 2 strokes now run in mx2 class.

queen of spodes wrote:

Not in the US at least not on the pro level

Timo_2824 wrote:

Pro's wouldn't race 2 strokes anyway, at least anyone who is fast enough to win.

Are you kiddin me?
Mattia Guadagnini, does it sound familiar?
Go look his scores at the italian/international championship last year with his TC 250 2 stroke.

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rarararaataatatatata

7/22/2020 2:06 PM

Didn't Chris Alldredge have a 250 2 stroke in the top ten in the 450 class a couple years ago in moto 1 at Glen Helen before having a flat? And that place is a horse power track.

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2018 KX450F
2005 KX250
2003 KDX 220
1984 KX 80
1982 RM 80
1980 RM 80
1977 XR 75
1969 Honda Mini 50

7/22/2020 3:10 PM

queen of spodes wrote:

Not in the US at least not on the pro level

Timo_2824 wrote:

Pro's wouldn't race 2 strokes anyway, at least anyone who is fast enough to win.

queen of spodes wrote:

Canada but still:

And didn't they change the rules after Kaven won the cship? Basically banned any mod on a 250 2stk forward of the intake, sans a pipe. Honda and Kawi supposedly threw a tantrum and got their way.

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7/22/2020 3:46 PM
Edited Date/Time: 7/22/2020 4:32 PM

Timo_2824 wrote:

Pro's wouldn't race 2 strokes anyway, at least anyone who is fast enough to win.

queen of spodes wrote:

Canada but still:

RACERX69 wrote:

And didn't they change the rules after Kaven won the cship? Basically banned any mod on a 250 2stk forward of the intake, sans ...more

They changed the rules twice due to Kaven's championships on the 2-stroke:

For his first championship, he rode both a modified 4-stroke and mod 2-stroke KTM 250 for different traction conditions. So CMRC eliminated that choice, disallowing riders to switch throughout the series. They also ruled that there can be no engine mods for a 2-stroke, but 4-strokes could still be built up. Despite the rule change, based on his lap-times Kaven chose the stock-engine SX250 over a modified 4T as the faster bike to defend his title.

Then, after he won the second title on the stock 2T, they changed the rules again, disallowing any rider who had previously finished in the top 5 from running a 2-stroke, which finally eliminated even stock two-strokes from being in the hands of a likely championship contender.

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7/22/2020 3:55 PM

Pros in aust were able to run 250 2 strokes with the 250 4 strokes.

The 250 four strokes were still king.

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7/22/2020 3:57 PM

GasGasOrAss wrote:

Why do 4 strokes have higher HP rating when a 2 stroke of half the displacement is comparable in speed?

No mystery.
Current 2 strokes do not make quite double the power of a similar capacity modern 4 stroke.
But nearly.
The 2 stroke is lighter, but arguably, more “difficult” to ride.

As the 4 strokes have continued to develop it’s pretty well accepted that a 125cc 2 stroke is at a disadvantage compared to a 250cc 4 stroke. Same situation with 250cc 2T V 450cc 4T.

Many believe the disparity in capacity 2t V 4t should be reduced, or removed.
As mentioned above running a 250 2T in the “250” class (full of 4 strokes) is legal in some places (Canada? Australia?)

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7/22/2020 4:41 PM

I wish they would just allow full mod 250s of any stroke to compete so this debate could finally end

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7/22/2020 4:59 PM

tobz wrote:

Pros in aust were able to run 250 2 strokes with the 250 4 strokes.

The 250 four strokes were still king.

Apart from when Egan Mastin won the championship on a two stroke.

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7/22/2020 5:07 PM

I would love a true Pro Open class. Run what ya brung, whatever you want, any displacement, any stroke. Whatever you think you're the fastest on bring it. Like local Vet classes.

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7/22/2020 5:12 PM

tobz wrote:

Pros in aust were able to run 250 2 strokes with the 250 4 strokes.

The 250 four strokes were still king.

pdub187 wrote:

Apart from when Egan Mastin won the championship on a two stroke.

This is why the post was in past tense, as I’ve not followed the Aussie nationals for years. Never heard of Egan Mastin.

Touch, play on!

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