CMRC Stock Motor Rule

ChrisB10
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ChrisB10
Edited Date/Time 5/29/2015 1:46pm
According to Matthes all motors must be stock this season. The guys on the podcast discussing it weren't fans of the rule but I like it. It will be tough to enforce but I think it's more fair that way. It should be more about rider than bike and unfortunately today a lot of privateers have the skills but not the $ to compete.....
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Flatliner
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Flatliner 5/28/2015 11:55am
5/28/2015 11:55am
ChrisB10 wrote:
According to Matthes all motors must be stock this season. The guys on the podcast discussing it weren't fans of the rule but I like it...
According to Matthes all motors must be stock this season. The guys on the podcast discussing it weren't fans of the rule but I like it. It will be tough to enforce but I think it's more fair that way. It should be more about rider than bike and unfortunately today a lot of privateers have the skills but not the $ to compete.....
I don't like it. A built 250f is going to have more juice than a stock ktm or yz 250. Should have left it the way it was.
scooter5002
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scooter5002 5/28/2015 11:58am
5/28/2015 11:58am
Caving in to the OEM's, who were bitching about losing to built 2 stokes, after dumping large into their factory team motors. Something about an "unfair advantage". Guess it's not one rule for all, after all.
mtl
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mtl 5/28/2015 12:03pm
5/28/2015 12:03pm
Stock only for 250 2 Strokes?

or stock for 250F and 250 2 Stroke?

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sybro
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sybro 5/28/2015 1:25pm
5/28/2015 1:25pm
2 stroke only
slipdog
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slipdog 5/28/2015 2:10pm
5/28/2015 2:10pm
Flatliner wrote:
I don't like it. A built 250f is going to have more juice than a stock ktm or yz 250. Should have left it the way...
I don't like it. A built 250f is going to have more juice than a stock ktm or yz 250. Should have left it the way it was.
No they won't
Flatliner
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Flatliner 5/28/2015 2:30pm
5/28/2015 2:30pm
Flatliner wrote:
I don't like it. A built 250f is going to have more juice than a stock ktm or yz 250. Should have left it the way...
I don't like it. A built 250f is going to have more juice than a stock ktm or yz 250. Should have left it the way it was.
slipdog wrote:
No they won't
I know you build bikes, but I watched the races last year. The two strokes weren't killing the 250f's motor wise.
slipdog
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slipdog 5/28/2015 2:46pm
5/28/2015 2:46pm Edited Date/Time 5/28/2015 2:47pm
Flatliner wrote:
I don't like it. A built 250f is going to have more juice than a stock ktm or yz 250. Should have left it the way...
I don't like it. A built 250f is going to have more juice than a stock ktm or yz 250. Should have left it the way it was.
slipdog wrote:
No they won't
Flatliner wrote:
I know you build bikes, but I watched the races last year. The two strokes weren't killing the 250f's motor wise.
Sorry for not being more descriptive, I was on my phone at the park with my son.

The built 250f won't have "more" juice, but in many cases "better" juice which allows them to be just as competitive like when JMart turns the same lap times as Dungey does on a 450. I thought the whole rule stemmed from a team owner complaining that their built 250f couldn't match the 2t in pure power off the start. Personally I'm totally fine with the way the rule was.
ratonmacias
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ratonmacias 5/28/2015 3:06pm
5/28/2015 3:06pm
crap rule. They are afraid of bikes that are 10 years old.
ratonmacias
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ratonmacias 5/28/2015 3:09pm
5/28/2015 3:09pm
If they wanted it fair they would set a limit based on money spent For either type of engine. A good tuner can do wonders on a 2 stroke for the same amount of money a titanium carbon fiber twin pipe system runs.
Falcon
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Falcon 5/28/2015 4:00pm
5/28/2015 4:00pm
It makes perfect sense to me. You have to cripple the more powerful motor somehow or everyone would start using it.Can't have that.
MxKing809
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MxKing809 5/28/2015 4:16pm
5/28/2015 4:16pm
Hopefully KTM will make a SXS version of the 250 like they do the 50's. That way it would be 'stock'
Flatliner
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Flatliner 5/28/2015 4:35pm
5/28/2015 4:35pm
slipdog wrote:
No they won't
Flatliner wrote:
I know you build bikes, but I watched the races last year. The two strokes weren't killing the 250f's motor wise.
slipdog wrote:
Sorry for not being more descriptive, I was on my phone at the park with my son. The built 250f won't have "more" juice, but in...
Sorry for not being more descriptive, I was on my phone at the park with my son.

The built 250f won't have "more" juice, but in many cases "better" juice which allows them to be just as competitive like when JMart turns the same lap times as Dungey does on a 450. I thought the whole rule stemmed from a team owner complaining that their built 250f couldn't match the 2t in pure power off the start. Personally I'm totally fine with the way the rule was.
Quality time! I agree with your post, and I think it was a few teams who made a fuss.
ChrisB10
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ChrisB10 5/28/2015 4:57pm
5/28/2015 4:57pm Edited Date/Time 5/28/2015 5:00pm
oh i didn't know it was 2 stroke only I was doing stuff around the house while listening and missed some parts
Crush
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Crush 5/28/2015 5:03pm
5/28/2015 5:03pm
I believe it's the same as the Aussie rule right, stock from airboot to exhaust ports... so filter/pipes/exhaust only and jetting of course...

Everyone needs to stop looking at the horsepower numbers and look at actual average lap times. Handling and engine characteristics obviously play a huge part too. It's not like two strokes are blowing everyone out the water in that class, they're actually really close.

Benoit was a better rider than Friese etc last year. Clout and Styke were the better guys than Makeham and any of the two stroke guys down here. It averages out pretty well and actually provides a lot of interest watching the strengths and weaknesses of each motor come into play around a track.
Ebs
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Ebs 5/28/2015 7:18pm
5/28/2015 7:18pm
For the 2015 CMRC Rockstar Energy Drink MX Nationals, the following amended rules will apply to 250 two-stroke motorcycles in order to be eligible for competition:

1. The bike must remain in stock form from the intake manifold to the exhaust port, and all engine parts between those two points. All engine parts (ie. cylinder, cylinder head, piston, rings, rod, etc.) must be OEM for that year model.
2. Intake manifold is defined from the rubber boot clamps to the carburetor. No porting or headwork allowed.
3. There are no restrictions on pipes or mufflers other than the fact that they must meet the sound rules.
4. CMRC will be conducting random engine checks throughout the series. CMRC will have a cylinder, cylinder head and piston from each manufacturer for comparison.
5. Any bikes found to be modified will be excluded from the results of the day’s competition.
6. Additionally, a rider may not switch from a two-stroke to a four-stroke or visa-versa. The type of machine on which a rider begins the series is to be used to the completion (ie. Start on a two-stroke, finish on a two-stroke).

http://www.cmrcracing.com/amended-250-two-stroke-rule-2015-nationals/
enketchum
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enketchum 5/28/2015 7:41pm
5/28/2015 7:41pm
Can you work on the ports of a cylinder or does it just need to be a stock part?
ML512
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ML512 5/28/2015 7:45pm
5/28/2015 7:45pm
enketchum wrote:
Can you work on the ports of a cylinder or does it just need to be a stock part?
No cylinder porting.

Pit Row

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burn1986
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burn1986 5/28/2015 9:00pm
5/28/2015 9:00pm Edited Date/Time 5/28/2015 9:01pm
It doesn't sound that bad. At least they allow them to race in the 250 class! Sounds like the Canadians have guts, unlike some promoters and the AMA.
Kawasaki572
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Kawasaki572 5/29/2015 2:45am
5/29/2015 2:45am
With a perfectly jetted carb, filter, and the best possible silencer and pipe combo (Or anymore possible/legal modifications), how much more HP than bone stock?

I remember MXA did a silencer/pipe test on the YZ250. The PC pipe/silencer made the most, with about 3 more HP, putting the YZ on par with the KTM making 49HP.

Also, how much HP will the 250f's make from the top teams at the CMRC?
PEPE001
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PEPE001 5/29/2015 5:35am
5/29/2015 5:35am
So KTM likes the rule there are fast right out of the box.
YZ need a little help to get on par with KTM.
scooter5002
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scooter5002 5/29/2015 8:47am
5/29/2015 8:47am
Kawasaki572 wrote:
With a perfectly jetted carb, filter, and the best possible silencer and pipe combo (Or anymore possible/legal modifications), how much more HP than bone stock? I...
With a perfectly jetted carb, filter, and the best possible silencer and pipe combo (Or anymore possible/legal modifications), how much more HP than bone stock?

I remember MXA did a silencer/pipe test on the YZ250. The PC pipe/silencer made the most, with about 3 more HP, putting the YZ on par with the KTM making 49HP.

Also, how much HP will the 250f's make from the top teams at the CMRC?
Can't recall for sure, but I think that pipe also sacrificed low and too end, for the the gain of the extra 3. Whether or not that would be a deal breaker is unknown, but a pro is in the saddle. Still, a hot rod 2 stroke would be the ticket at the Dunes. That place gets some nasty rough during the National.
Kawasaki572
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Kawasaki572 5/29/2015 1:46pm
5/29/2015 1:46pm
Kawasaki572 wrote:
With a perfectly jetted carb, filter, and the best possible silencer and pipe combo (Or anymore possible/legal modifications), how much more HP than bone stock? I...
With a perfectly jetted carb, filter, and the best possible silencer and pipe combo (Or anymore possible/legal modifications), how much more HP than bone stock?

I remember MXA did a silencer/pipe test on the YZ250. The PC pipe/silencer made the most, with about 3 more HP, putting the YZ on par with the KTM making 49HP.

Also, how much HP will the 250f's make from the top teams at the CMRC?
scooter5002 wrote:
Can't recall for sure, but I think that pipe also sacrificed low and too end, for the the gain of the extra 3. Whether or not...
Can't recall for sure, but I think that pipe also sacrificed low and too end, for the the gain of the extra 3. Whether or not that would be a deal breaker is unknown, but a pro is in the saddle. Still, a hot rod 2 stroke would be the ticket at the Dunes. That place gets some nasty rough during the National.
Here's the link.

http://motocrossactionmag.com/news/searching-for-the-ultimate-2013-yz250-two-stroke-exhaust-pipe-dyno-charts-test-rider-comments-ratings-by-pros-intermediates-and-novices

Yeah, it traded a bit of low end for mostly top. The PC silencer/pipe made the most HP, and the DR. D silencer made the most torque, almost a full 2 ft-lbs of torque than the stock silencer/pipe.

Anyone know who is riding a 2 stroke? Rules says if a competitor rides a 2 stroke at the first round, He/she has to ride it the whole season, same for the 4 stroke. Hope there's a few top guys riding them.

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