RM250 2 STROKE

mx_563
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mx_563 12/31/2012 12:46am
12/31/2012 12:46am Edited Date/Time 1/1/2013 7:10am
I've got an 04 RM250 and an 08' CRF450R. I think I've reached dirt bike nirvana. I've ridden newer bikes but nothing blew me away so I'm sticking with this combo for a while.

BTW: I had an 06 YZ250 for a while but didn't like the quality of the KYB suspension components and the motor felt too tame compared to my RM250.
Travis_Hudson 12/31/2012 1:14pm
12/31/2012 1:14pm
Has anyone ever tried a flywheel for mx on a 04 or newer cr250r?
CamP
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CamP 12/31/2012 2:46pm
12/31/2012 2:46pm
Travis_Hudson wrote:
Has anyone ever tried a flywheel for mx on a 04 or newer cr250r?
I have a 8oz flywheel weight on my '07 CR250. It works great for my setup.
Motodude
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Motodude 12/31/2012 3:15pm
12/31/2012 3:15pm

Perhaps the best 250 2 stroke made if you can find one.

The Shop

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Travis_Hudson 12/31/2012 4:39pm
12/31/2012 4:39pm
Travis_Hudson wrote:
Has anyone ever tried a flywheel for mx on a 04 or newer cr250r?
CamP wrote:
I have a 8oz flywheel weight on my '07 CR250. It works great for my setup.
Hey camP,......what gearing do you run on yours...13/48?
CamP
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CamP 12/31/2012 6:04pm
12/31/2012 6:04pm
Travis_Hudson wrote:
Has anyone ever tried a flywheel for mx on a 04 or newer cr250r?
CamP wrote:
I have a 8oz flywheel weight on my '07 CR250. It works great for my setup.
Travis_Hudson wrote:
Hey camP,......what gearing do you run on yours...13/48?
My modified engine has enough low/mid to pull 13/48 on a fast track, but I'm currently running the stock 13/49 gearing, which requires less clutching on technical tracks.
Travis_Hudson 12/31/2012 11:07pm
12/31/2012 11:07pm
CamP wrote:
My modified engine has enough low/mid to pull 13/48 on a fast track, but I'm currently running the stock 13/49 gearing, which requires less clutching on...
My modified engine has enough low/mid to pull 13/48 on a fast track, but I'm currently running the stock 13/49 gearing, which requires less clutching on technical tracks.
Who modified your engine if I might ask?.......I am looking to do the whole engine top to bottom in about a month and I have a 50t. (which is what it came with) and it seems like always have to shift right before a jump.......and when ido it's not quite where it should be in the rpms.
retrofun
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retrofun 1/1/2013 12:27am
1/1/2013 12:27am Edited Date/Time 1/1/2013 12:41am
Ive been considering adding a flywheel weight to my 08, which i purchased in november 2011, i rode this season without one, but after trying a 04 that was lent to me that did have a 8oz installed, i will getting one, to use for certain track conditions.
CamP
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CamP 1/1/2013 6:01am
1/1/2013 6:01am
CamP wrote:
My modified engine has enough low/mid to pull 13/48 on a fast track, but I'm currently running the stock 13/49 gearing, which requires less clutching on...
My modified engine has enough low/mid to pull 13/48 on a fast track, but I'm currently running the stock 13/49 gearing, which requires less clutching on technical tracks.
Travis_Hudson wrote:
Who modified your engine if I might ask?.......I am looking to do the whole engine top to bottom in about a month and I have a...
Who modified your engine if I might ask?.......I am looking to do the whole engine top to bottom in about a month and I have a 50t. (which is what it came with) and it seems like always have to shift right before a jump.......and when ido it's not quite where it should be in the rpms.
I had a machinist friend mill .030" off the base of the cylinder, which raised the compression and reduced all the port timing.
With the 05-07 CR250, the squish is generally about .080", which is .030" too much. Taking .030" off the base corrects this. This boosted low/mid power which allows me to pull a taller gear, and widens the spread of power. I also installed a YZ250 TPS carb, which also improves low/mid and also tolerates wider temperature swings. The cranking pressure is now 235psi, so it requires race gas or 100LL avgas.

The 02-04 usually has around .060" of squish. Running a thinner 05-07 base gasket will correct it and give you a smaller improvement without any machine work. The engine will respond even further by milling the base, but you will also have to machine the squish band in the head to get the squish back up to .050".
shawn206
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shawn206 1/1/2013 9:03am
1/1/2013 9:03am
Is there a flywheel weight that does not require a spacer for the ignition cover?
Digger29
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Digger29 1/1/2013 9:09am
1/1/2013 9:09am
Speaking of flywheel weights. I just did the motor on my 13 KTM250SX (lowering the & cleaning up the cylinder & doing the head & powervalve & boring the carb) & the guy who did most of the work was at my house this morning getting some thinner base gaskets so he could lower the cylinder on a friends of ours new 13 250SX too & I was telling him about this topic & he said to take a look at the size of the flywheel weight that comes stock on my bike. He said it appears to easily be around 20-25oz.
CamP
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CamP 1/1/2013 9:43am
1/1/2013 9:43am
shawn206 wrote:
Is there a flywheel weight that does not require a spacer for the ignition cover?
Generally, 8 and 10oz weights don't require spacers on big bikes.
cool_hand
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cool_hand 1/1/2013 9:44am
1/1/2013 9:44am


I got this bad boy about a year and a half ago and I really like it....very nimble, quick. Such a deal for $1500.
Travis_Hudson 1/1/2013 5:28pm
1/1/2013 5:28pm
cool_hand wrote:
[img]https://p.vitalmx.com/photos/forums/2013/01/01/20121225_174525_297594.jpg[/img] I got this bad boy about a year and a half ago and I really like it....very nimble, quick. Such a deal for $1500.


I got this bad boy about a year and a half ago and I really like it....very nimble, quick. Such a deal for $1500.
I picked my honda up for $1800. there are such good deals on these things out there if you just look around.
web mx
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web mx 1/1/2013 6:38pm
1/1/2013 6:38pm
As you can see in my avatar pic thats my 04 rm250 [ have also had 92,96,00,04] The last 2 years I raced in 04-05, I raced our Fair supercross series in +25,+30,+35 and 250A expert classes and although my bike was stock except for fmf fatty pipe and shorty silencer I got 90%+ of the holeshots even against alot of 450's and the young punks in A class that couldnt believe a 36/37 year old [old man] on a 2-stroke was beating them...esp. on the starts...Lol..Those suzuki's just seemed to rip if ya knew how to short shift em....I sold the 04 a couple years ago and now want to get back into it and am looking for another 05--08 rm
malachi177
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malachi177 1/1/2013 8:32pm
1/1/2013 8:32pm
Digger29 wrote:
Speaking of flywheel weights. I just did the motor on my 13 KTM250SX (lowering the & cleaning up the cylinder & doing the head & powervalve...
Speaking of flywheel weights. I just did the motor on my 13 KTM250SX (lowering the & cleaning up the cylinder & doing the head & powervalve & boring the carb) & the guy who did most of the work was at my house this morning getting some thinner base gaskets so he could lower the cylinder on a friends of ours new 13 250SX too & I was telling him about this topic & he said to take a look at the size of the flywheel weight that comes stock on my bike. He said it appears to easily be around 20-25oz.
Your '13 comes stock with a flywheel weight of about 20-25 ozBlink .....now that's cool. A manufacturer that is catching on, I like that.
shawn206
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shawn206 1/2/2013 9:49am
1/2/2013 9:49am Edited Date/Time 1/2/2013 9:53am
2006 with 6 hours on it. I just picked it up last week in the Atlanta area on Craigslist. I will try to post a picture of it.
Digger29
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Digger29 1/2/2013 12:22pm
1/2/2013 12:22pm Edited Date/Time 1/2/2013 12:23pm
Digger29 wrote:
Speaking of flywheel weights. I just did the motor on my 13 KTM250SX (lowering the & cleaning up the cylinder & doing the head & powervalve...
Speaking of flywheel weights. I just did the motor on my 13 KTM250SX (lowering the & cleaning up the cylinder & doing the head & powervalve & boring the carb) & the guy who did most of the work was at my house this morning getting some thinner base gaskets so he could lower the cylinder on a friends of ours new 13 250SX too & I was telling him about this topic & he said to take a look at the size of the flywheel weight that comes stock on my bike. He said it appears to easily be around 20-25oz.
malachi177 wrote:
Your '13 comes stock with a flywheel weight of about 20-25 ozBlink .....now that's cool. A manufacturer that is catching on, I like that.
Ya, my motor is on my workbench. I'm getting my frame powdercoated orange. I'll take a pic of the flywheel weight later on when I get home. It's huge & it looks twice as thick & quite a bit larger than the 14oz that I had on my RM250. This KTM is just a blast to ride. It's super tractable yet it is super snappy & 2 strokey at the same time if that makes any sense & it does everything that a 4 stroke can do & some things that they can't. It is the best 2 stroke power & delivery of it that I've ever ridden.

Pit Row

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CrashMaster
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CrashMaster 1/7/2013 6:12am
1/7/2013 6:12am
WOW, thanks for all the info and then some on the RM's. So it looks as though I will be searching for a good con. 05 and up RM250. Man im SUPER PUMPED!!!Wink
Pal
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Pal 2/4/2013 2:21pm
2/4/2013 2:21pm




Here's my '08, it's not had much use yet but will change this year. It has a couple of PC extras: ti pegs, linkage & exhaust.
crf250pilot
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crf250pilot 2/4/2013 2:58pm
2/4/2013 2:58pm
Pal wrote:
[img]https://p.vitalmx.com/photos/forums/2013/02/04/DSCF0851_769872.JPG[/img] [img]https://p.vitalmx.com/photos/forums/2013/02/04/DSCF0858_26685.JPG[/img] Here's my '08, it's not had much use yet but will change this year. It has a couple of PC extras: ti pegs, linkage...




Here's my '08, it's not had much use yet but will change this year. It has a couple of PC extras: ti pegs, linkage & exhaust.
Maybe you can trade someone those TI pegs for a chain, bet it will go faster.
malachi177
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malachi177 2/4/2013 5:44pm
2/4/2013 5:44pm
Pal wrote:
[img]https://p.vitalmx.com/photos/forums/2013/02/04/DSCF0851_769872.JPG[/img] [img]https://p.vitalmx.com/photos/forums/2013/02/04/DSCF0858_26685.JPG[/img] Here's my '08, it's not had much use yet but will change this year. It has a couple of PC extras: ti pegs, linkage...




Here's my '08, it's not had much use yet but will change this year. It has a couple of PC extras: ti pegs, linkage & exhaust.
holy crapWoohoo ....nice bike!!
Growboxracers
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Growboxracers 4/17/2013 4:59pm
4/17/2013 4:59pm
I'm thinking an Eric Gorr 265 Kit, V Force Reeds, Pro Circuit Pipe and a 6oz Stealthy Flywheel Weight would make a really good combo on our 06 and 08 RM250s for the 40+ class. I think this would be 50+ Horse (great for starts against 450s!) and would have a broader, more hooked up powerband, opinions?
donMX14
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donMX14 4/17/2013 5:21pm
4/17/2013 5:21pm Edited Date/Time 4/17/2013 5:23pm
This is a 04 i picked up last fall. I just finished it up last month. I rode it last weekend and had so much fun,
im now lookiing to trade my 450 for a 06-8 rm250.

donMX14
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donMX14 4/17/2013 5:31pm
4/17/2013 5:31pm
Growboxracers
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Growboxracers 4/17/2013 6:31pm
4/17/2013 6:31pm
I have a great condition Pro Circuit Pull Rod for sale, it fits 06-08 RM250. $100 includes ship in Continental US, PayPal is fine PM me if interested...
spindel
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spindel 4/17/2013 10:08pm
4/17/2013 10:08pm
Growboxracers wrote:
I'm thinking an Eric Gorr 265 Kit, V Force Reeds, Pro Circuit Pipe and a 6oz Stealthy Flywheel Weight would make a really good combo on...
I'm thinking an Eric Gorr 265 Kit, V Force Reeds, Pro Circuit Pipe and a 6oz Stealthy Flywheel Weight would make a really good combo on our 06 and 08 RM250s for the 40+ class. I think this would be 50+ Horse (great for starts against 450s!) and would have a broader, more hooked up powerband, opinions?
I have that almost exact combo on my 06 and use it in 35+ and 40+A classes. It is the best bike ive ever owned. KB5 265 cylinder and head mods dep pipe and silencer. V Force. And stealthy 6oz. It eats 450s up!
AS64
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AS64 4/17/2013 10:10pm
4/17/2013 10:10pm Edited Date/Time 4/17/2013 10:11pm
spindel wrote:
I have that almost exact combo on my 06 and use it in 35+ and 40+A classes. It is the best bike ive ever owned. KB5...
I have that almost exact combo on my 06 and use it in 35+ and 40+A classes. It is the best bike ive ever owned. KB5 265 cylinder and head mods dep pipe and silencer. V Force. And stealthy 6oz. It eats 450s up!
How is the power against the 450s?

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