Post by: Formerly knownas Premixed on January 31, 2013, 10:08:36 PM
So...... I'm swapping the motor and carburetor all together to the '99.
You can see my 03 motor was immaculate. I ran a PWK Airstryker off a KTM250SX and a DEP pipe and that was pretty good. Peaky, but good.
Surprising how close the mounts are.
My plan is to replicate this 2004 RC250M. Throttlejockey is supplying the graphics and number plates. I am using black wheels, and a '12 model front fender.
The bike has newer CRF Showa front and rear suspension which is being revalved by Bumpsticks tomorrow with some speed sensitive mid valving.
Post by: _X_ on January 31, 2013, 10:17:16 PM
Post by: Formerly knownas Premixed on January 31, 2013, 10:44:17 PM
I think im going to put a Scalvini on this thing too, with a Bud silencer.
Post by: _X_ on January 31, 2013, 10:53:14 PM
Post by: Stusmoke on January 31, 2013, 11:13:57 PM
Post by: Formerly knownas Premixed on January 31, 2013, 11:30:20 PM
Awesome idea and I'll be watching closely. What made you choose the 99 motor over the 2000 or 2001 motor?
The 99 has the best porting in the jug. Apparently, the 00-01 guy look for the 99 jug.
Ok so I pulled that motor apart, and not surprisingly, it's seized.
I said if i had to split the cases AND nikasil it, im going to 295ccs, so we shall see what the cylinder plating looks like (probably shit). Horrifying.
This motor was like a sand box inside. Someone probably ran the bike with no filter. There was grit all in it, both rings were stuck. Time to go all out and build a real 450-assraper.
Post by: Stusmoke on February 01, 2013, 01:38:55 AM
Awesome idea and I'll be watching closely. What made you choose the 99 motor over the 2000 or 2001 motor?
The 99 has the best porting in the jug. Apparently, the 00-01 guy look for the 99 jug.
Ok so I pulled that motor apart, and not surprisingly, it's seized.
I said if i had to split the cases AND nikasil it, im going to 295ccs, so we shall see what the cylinder plating looks like (probably shit). Horrifying.
This motor was like a sand box inside. Someone probably ran the bike with no filter. There was grit all in it, both rings were stuck. Time to go all out and build a real 450-assraper.
Sounds good to me. The last bit anyway. So long as the 450 hasn't been run for a couple of hours... ouch.
Are you doing the rebuild yourself?
Post by: GlennC on February 01, 2013, 05:08:46 AM
I have an 01 engine and I'm looking for a gen 3 cr 250 but I was under the impresion that the 01 engine would bolt in.
Post by: Formerly knownas Premixed on February 01, 2013, 06:50:43 PM
Yea, of course I'm rebuilding the thing myself.
Post by: Super Trucker on February 01, 2013, 07:02:11 PM
I don't think so. They just intended for their RC Valve motor to not suck, which requires a little longer intake tract, more compression, a little less crankcase volume, and a Keihin carb. They'd have gotten around to it, but they built foopers instead. This 99 motor was long in the tooth by 01. It went from 92 (Jeff Stanton era) to 2001 with only small changes.Sounds like a great project, I rode a pals 99 cr250 it had a amazing motor, lineer feel but strong, it had low end into a strong mid then it never stopped pulling. I left it wide open to see when it signed off, I was shocked it just kept pulling on the topend.
I think im going to put a Scalvini on this thing too, with a Bud silencer.
Post by: Formerly knownas Premixed on February 01, 2013, 07:30:57 PM
I might do a 270 out of this, as long as I can avoid Gorr. Maybe rpm or pr2.
Post by: Formerly knownas Premixed on February 01, 2013, 10:53:32 PM
rpm manufacturing does a 270 kit, with piston for not much more than a standard strip and re-plate job.
I haven't done the math yet, but with the 3-4 options Eddie Sanders offers on rod length, something like a 300cc should be easy.
My destroyed crank is a hot rods, so i am going to call them and find out about getting it rebuilt. Supposedly those guys are "real", and by real i mean, not a warehouse in China, but rather a machine shop in the USA.
I just want to cheat as hard as possible for the 250 class. Something like a 60hp 300cc two stroke against a 37hp 250 fourstroke. I have to mention I am kidding, I forget sometimes that people take this seriously. But no, seriously, some 250F kid is going to take a shit in his pants.
Post by: _X_ on February 01, 2013, 11:10:12 PM
Post by: TMKIWI on February 02, 2013, 04:28:41 AM
Nice build btw.
Post by: citabjockey on February 02, 2013, 06:36:11 AM
If you were formerly known as premixed, What do we call you now.
Nice build btw.
Post by: scotty dog on February 02, 2013, 01:49:45 PM
Preliminary research find me looking at a company called Eddie Sanders racing. They use 92-01 CR250 motors for micro sprint cars. They have a long rod stroker crank that they sell for not much more than a hot rods oem replacement crank.I like your way of thinkin premixed, who's gonna know how big it is? As long as it has "250" stickers on it.
rpm manufacturing does a 270 kit, with piston for not much more than a standard strip and re-plate job.
I haven't done the math yet, but with the 3-4 options Eddie Sanders offers on rod length, something like a 300cc should be easy.
My destroyed crank is a hot rods, so i am going to call them and find out about getting it rebuilt. Supposedly those guys are "real", and by real i mean, not a warehouse in China, but rather a machine shop in the USA.
I just want to cheat as hard as possible for the 250 class. Something like a 60hp 300cc two stroke against a 37hp 250 fourstroke. I have to mention I am kidding, I forget sometimes that people take this seriously. But no, seriously, some 250F kid is going to take a shit in his pants.
I liked the 98 a little better than the 99 , was a bit stronger mid to top I thought, mine was s screamer, loved it
Post by: Brap on February 04, 2013, 02:34:29 PM
Post by: Formerly knownas Premixed on February 04, 2013, 02:39:49 PM
At this point I am looking at it thinking, It needs nikasil, it needs new engine cases, it needs a crank, it needs reeds, it needs 80 dollars in powervalve parts. It needs radiators and an 01 pipe. I just do not want to alter the crank case by grinding it to try and fix all the destruction in there. I am sure someone can fix it, so I am going to inquire about that.
It's really starting to look less and less "worth it" as all my 03 motor needs is a piston. So, we'll see. I still want the HPP motor in there badly.
Post by: Brap on February 04, 2013, 02:47:16 PM
Post by: Formerly knownas Premixed on February 04, 2013, 02:50:14 PM
You have any idea as to what 250 motor was the strongest off the line?
Honda? 97-01 were the best 250 motors they ever made, but the 97-99 and 00-01 chassis sucked. in 03 they got the chassis right, in 04 they got the forks right, but from 02-07 the motor was weak. it made 45-46hp like the 97-01 motor, but it made it like a 125. no bottom, no mid, then a 2,000rpm punch, then it falls on it's face if you don't shift it. It's hard to even ride the clutch.
Post by: Brap on February 04, 2013, 02:53:49 PM
Post by: Formerly knownas Premixed on February 04, 2013, 03:11:47 PM
The 03+ KX, and 04+ RM are both clones of the YZ 02+ YZ. . Honda did it's own thing in 02 with the RC valve motor, and like I said, it's got no low end because the crank case volume is too high and the intake on the case reed motor is too short. It's like a road racing motor, which is no surprise as I am hearing the whole RC valve idea came from the NSR department.
Post by: _X_ on February 04, 2013, 08:48:17 PM
Post by: Formerly knownas Premixed on February 05, 2013, 12:33:09 AM
low end is for trail riding.
oh.
Post by: moto867 on February 05, 2013, 02:59:14 AM
Post by: 2T Institute on February 05, 2013, 05:24:15 AM
The best motor is the 04+ KTM. It scared MC into retirement.
The 03+ KX, and 04+ RM are both clones of the YZ 02+ YZ. . Honda did it's own thing in 02 with the RC valve motor, and like I said, it's got no low end because the crank case volume is too high and the intake on the case reed motor is too short. It's like a road racing motor, which is no surprise as I am hearing the whole RC valve idea came from the NSR department.
No such thing as too high case volume, servo pv operation is far superior to crank governed, if the engine has no bottom end the pipe will be the culprit. Fitting a servo power valve control will iron out dips in torque curves in minutes.
Post by: Formerly knownas Premixed on February 05, 2013, 02:15:34 PM
mc retired in 02
Incorrect. He retired in January 2003, on KTM, to get out of his 2 year KTM contract (retirement clause). He had a gnarly off-season testing crash, the motor was so strong he requested to ride it in stock form, plus, KTM promised him linkage, and never delivered. put all of that together and he said "fuck it".
Post by: Formerly knownas Premixed on February 05, 2013, 02:19:46 PM
The best motor is the 04+ KTM. It scared MC into retirement.
The 03+ KX, and 04+ RM are both clones of the YZ 02+ YZ. . Honda did it's own thing in 02 with the RC valve motor, and like I said, it's got no low end because the crank case volume is too high and the intake on the case reed motor is too short. It's like a road racing motor, which is no surprise as I am hearing the whole RC valve idea came from the NSR department.
No such thing as too high case volume, servo pv operation is far superior to crank governed, if the engine has no bottom end the pipe will be the culprit. Fitting a servo power valve control will iron out dips in torque curves in minutes.
How many RC valve CR250s have you owned/built/ridden/raced?
fitting a servo valve means nothing if the actuation point is wrong.
2T Institute, here is a guy who learned it by "doing it". All of the flaws of the motor that I found were solidified here. Give it a read, you might learn something.
Its a combination of things, starting at a TMX Mikuni carb with a slide that doesnt seal well, rolling in to a case reed induction that is too short, into a crank case that is too volumuous, into a cylinder head with way too much squish, and a poorly shaped band all together. PArt of it could be the pipe, which could be why Scalvinis pipe for this bike is so radically different than the FMF and PC.
http://www.thumpertalk.com/topic/639710-diy-cr250-engine-porting/page__hl__%20cr250%20%20self%20%20porting
Post by: _X_ on February 06, 2013, 06:31:22 PM
Post by: Super Trucker on February 06, 2013, 07:04:12 PM
Post by: 2T Institute on February 07, 2013, 04:15:08 AM
Haha, you're f*cking hilarious. Why so defensive?
Do you have the software to adjust the operating range of the RC valve? Or are you doing more of that internet virtual tuning you're so great at? My aunt might have balls but I don't want to believe she might be my Uncle...
I'm still waiting for you to tell me about all the races you've competed in on a last generation CR250, since your knowledge on the power delivery of this motor is oh so extensive.
I'm a comedian. I realise the concept of linear power delivery and over rev not peak numbers is still an anathema to you. But that what makes lower lap times, where 1% throttle = 1% torque at the wheel. I don't need to compete I get a A grade rider to tell me. Did you ever make it to A grade?
Post by: _X_ on February 07, 2013, 04:19:03 AM
Post by: Stusmoke on February 07, 2013, 05:58:30 AM
Post by: _X_ on February 07, 2013, 06:03:24 AM
Post by: Stusmoke on February 07, 2013, 08:39:25 AM
stu, if you got to name drop, no clout with me. a grade rider, pfffft.
Huh?
Post by: chump6784 on February 07, 2013, 08:20:27 PM
The best motor is the 04+ KTM. It scared MC into retirement.
The 03+ KX, and 04+ RM are both clones of the YZ 02+ YZ. . Honda did it's own thing in 02 with the RC valve motor, and like I said, it's got no low end because the crank case volume is too high and the intake on the case reed motor is too short. It's like a road racing motor, which is no surprise as I am hearing the whole RC valve idea came from the NSR department.
So all the dick pulling and big noting aside I found my 07 RM to be very similar but a little more snappy than the 06 YZ i rode at the same time. The YZ was more linear and didnt have as much snap as the RM. I preferred the RM although it was probably less effective on the majority of tracks i rode.
I rode a fairly worn 05 ktm and the motor on that was very impressive. It hit hard and didnt stop pulling. When it had a full rebuild done it was downright scary. The next ktm i rode was my 2012 and it is hands down the best 250 2 stroke motor i have ridden. Controlled, linear power the whole way through the rev range. It still has that 2 stroke feel but hooks up so well and has power everywhere. The only place where it lacks is over rev, it falls off pretty quick up top, i cant hold a gear into some corners like i could on my rm without feeling the fall off in power.
I cant comment on the honda or kx as i haven't ridden a 250 from either of those brands
Post by: Stusmoke on February 07, 2013, 11:25:02 PM
The best motor is the 04+ KTM. It scared MC into retirement.
The 03+ KX, and 04+ RM are both clones of the YZ 02+ YZ. . Honda did it's own thing in 02 with the RC valve motor, and like I said, it's got no low end because the crank case volume is too high and the intake on the case reed motor is too short. It's like a road racing motor, which is no surprise as I am hearing the whole RC valve idea came from the NSR department.
So all the dick pulling and big noting aside I found my 07 RM to be very similar but a little more snappy than the 06 YZ i rode at the same time. The YZ was more linear and didnt have as much snap as the RM. I preferred the RM although it was probably less effective on the majority of tracks i rode.
I rode a fairly worn 05 ktm and the motor on that was very impressive. It hit hard and didnt stop pulling. When it had a full rebuild done it was downright scary. The next ktm i rode was my 2012 and it is hands down the best 250 2 stroke motor i have ridden. Controlled, linear power the whole way through the rev range. It still has that 2 stroke feel but hooks up so well and has power everywhere. The only place where it lacks is over rev, it falls off pretty quick up top, i cant hold a gear into some corners like i could on my rm without feeling the fall off in power.
I cant comment on the honda or kx as i haven't ridden a 250 from either of those brands
Ohhhh how I can't wait for my KTM... Hey did you put a different pipe on her? That might get a little bit more overrev out of it.
Post by: chump6784 on February 08, 2013, 12:53:31 AM
Post by: GlennC on February 08, 2013, 04:59:51 AM
I don't need to modify the engine though, I'm an off road rider and the stock 01 is perfect for that.
I rode the 01 and 02 back to back, and the 01 feels so much stronger down low.
Post by: Stusmoke on February 09, 2013, 06:26:45 AM
Na not yet, the pro circuit gives it more over rev but I am waiting to wreck the stock one first. The only thing I have done to it is heavier fork springs and fork revalve.
Sweet, I envy you. Got any advice for when I get mine?
Post by: chump6784 on February 09, 2013, 06:18:52 PM
Get the suspension sprung and valved for you and ride it. The bike has more than enough power in stock form and it is smooth and easy to use.Na not yet, the pro circuit gives it more over rev but I am waiting to wreck the stock one first. The only thing I have done to it is heavier fork springs and fork revalve.
Sweet, I envy you. Got any advice for when I get mine?
Post by: Stusmoke on February 09, 2013, 08:57:15 PM
Get the suspension sprung and valved for you and ride it. The bike has more than enough power in stock form and it is smooth and easy to use.Na not yet, the pro circuit gives it more over rev but I am waiting to wreck the stock one first. The only thing I have done to it is heavier fork springs and fork revalve.
Sweet, I envy you. Got any advice for when I get mine?
That was my plan. Thanks for that. I think 50 HP is heaps for a motocross or supercross application I definitely wasn't planning on getting motor work done
Post by: scotty dog on February 09, 2013, 10:19:33 PM
Now that this thread has been turned into a popularity contest I think I would rather hear about updates on the CR project by Premixed...Me too, 2T why do you have to debate everything anyone puts up? Im pretty sure youre the one who pissed Premixed off first time with the 80 hp CR 500 thread!
I dont see much good come from what you post, its always negativity towards other people..
Post by: Stusmoke on February 09, 2013, 10:45:09 PM
Post by: 2T Institute on February 10, 2013, 12:40:42 AM
Me too, 2T why do you have to debate everything anyone puts up? Im pretty sure youre the one who pissed Premixed off first time with the 80 hp CR 500 thread!
I dont see much good come from what you post, its always negativity towards other people..
The only negativity I have is toward bullshit. I explain why it's bullshit and it isn't me who goes into a tailspin
I never banned anyone from this forum, free to come free to go. So where is that 80hp CR then anyway ? Can we see the video of it on the dyno?
Post by: Stusmoke on February 10, 2013, 12:43:27 AM
Me too, 2T why do you have to debate everything anyone puts up? Im pretty sure youre the one who pissed Premixed off first time with the 80 hp CR 500 thread!
I dont see much good come from what you post, its always negativity towards other people..
The only negativity I have is toward bullshit. I explain why it's bullshit and it isn't me who goes into a tailspin
Or we could just accept that it was a random number pulled out of the air and not care anymore?
Post by: ford832 on February 10, 2013, 01:31:07 AM
No such thing as too high case volume, servo pv operation is far superior to crank governed, if the engine has no bottom end the pipe will be the culprit. Fitting a servo power valve control will iron out dips in torque curves in minutes.
That's overly simplistic .Slapping a pipe on those years CR's doesn't make it a firebreather.Servo PV's work well when they work,but have their own set of issues and the difference in performance is marginal.
As for case volume,stuffing is often times done to alter flow direction as opposed to changing volume.Volume changes from stock are inconsequential-to a degree anyway.
None of this really matters though-hows the bike coming along?
Post by: Brap on February 11, 2013, 06:27:13 PM
Post by: _X_ on February 11, 2013, 06:33:52 PM
Post by: ford832 on February 11, 2013, 07:15:48 PM
You guys have nothing better to do than argue?
Speaking for myself,no,not at the moment.
Besides,good debate is the best way to solidify your position,or change your mind-or bits of both.Never stop learning.
Post by: Formerly knownas Premixed on March 04, 2013, 09:15:26 PM
Here is bullshit.
"You can adjust the servo powervalve in ____ rpm increments." -2T institute
Show me your Honda RC Valve adjustment tool/software. Go ahead, I want to see you adjust the engagement of the Honda RC Valve. Where is your "video". Because if you don't post a video of something, it's not good enough for 2T Institute.
You make this forum more and more like vital everytime I check back. You're a f*cking douche, period. I don't do this internet shit because of people exactly like yourself. Everything is an argument, everything is a debate. Everything is bullshit. You're negative, and negativity is contagious. Look at the comment columns on yahoo news stories. its all negative douchebags like yourself. most forums are the same way. you put a couple negative people in there, and it starts spreading. The next thing you know, everyone is the same cynical, sarcastic, negative toolbag.
I have ridden/raced this CR250 for half a season. and guess what...it has no low end. It's gutless off the bottom. So, don't come in here, tell me the crank case volume is perfect, you can adjust the powervalve blah blah blah based on what you "read" somewhere in some kiwi forum. Get out there, and race a CR250. Otherwise, shut the f*ck up and keep tapping away at your sperm stained keyboard.
Now, for those of you who give a shit, I have acquired some Kashima coated upper fork legs off an 09 Kawasaki, and DLC coated lowers. That's the dark, copper coated uppers and black coated lowers. I figure it will go well with the "RC250" theme. My seat cover came from Traction MX Seating, he was a pleasure to deal with, and was able to duplicate the seat cover on the RC250M perfectly, but with better more durable, gripper material. I highly recommend the guy. 43 dollars SHIPPED. and just as a reminder, I highly DO NOt recommend Eric Gorr, just had to throw that out there. he sucks.
I also recently found a killer deal on a 97 CR125, last year of the steel frame for the 125 and I am considering going and picking it up. My suspension guy has a et of the 2000 Showa conventional forks from an RM along with the brakes, yokes and a wheel that I could put on that CR125.
I don't know how much I'll keep up with this thread, as I like to keep my hobbies lighthearted and fun, which is impossible to do around here anymore, apparently. I'm also toying with the idea of a scalvini pipe on this bike. they're only about 30 bucks more than ap ro circuit. I have a fresh DEP on there now, but we'll see. I really want a cone pipe, and the expansion chamber colume on the Scalvini looks much different from the PC and FMF pipes, almost as if he figured out something.
Post by: _X_ on March 04, 2013, 09:43:45 PM
Post by: scotty dog on March 04, 2013, 09:45:49 PM
Post by: motoxr377 on March 04, 2013, 11:27:55 PM
Now, I like you.
Post by: msmola2002 on March 04, 2013, 11:36:31 PM
2T Institute, bullshit?
Here is bullshit.
"You can adjust the servo powervalve in ____ rpm increments." -2T institute
Show me your Honda RC Valve adjustment tool/software. Go ahead, I want to see you adjust the engagement of the Honda RC Valve. Where is your "video". Because if you don't post a video of something, it's not good enough for 2T Institute.
Not bullshit
I own one.
Post by: Stusmoke on March 05, 2013, 02:36:27 AM
Now, for those of you who give a shit, I have acquired some Kashima coated upper fork legs off an 09 Kawasaki, and DLC coated lowers. That's the dark, copper coated uppers and black coated lowers. I figure it will go well with the "RC250" theme. My seat cover came from Traction MX Seating, he was a pleasure to deal with, and was able to duplicate the seat cover on the RC250M perfectly, but with better more durable, gripper material. I highly recommend the guy. 43 dollars SHIPPED. and just as a reminder, I highly DO NOt recommend Eric Gorr, just had to throw that out there. he sucks.
I also recently found a killer deal on a 97 CR125, last year of the steel frame for the 125 and I am considering going and picking it up. My suspension guy has a et of the 2000 Showa conventional forks from an RM along with the brakes, yokes and a wheel that I could put on that CR125.
I don't know how much I'll keep up with this thread, as I like to keep my hobbies lighthearted and fun, which is impossible to do around here anymore, apparently. I'm also toying with the idea of a scalvini pipe on this bike. they're only about 30 bucks more than ap ro circuit. I have a fresh DEP on there now, but we'll see. I really want a cone pipe, and the expansion chamber colume on the Scalvini looks much different from the PC and FMF pipes, almost as if he figured out something.
I for one, have enjoyed following this thread and would like to see it continued. Also, the scalvani sounds like a good idea. If not for performance, then simply because they look badass.
Side note, how did the DEP go?
Post by: cnrcpla on March 05, 2013, 02:38:57 AM