02 cr125 Dyno

steve125

steve125

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Oct 19, 2000
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marcusgunby

marcusgunby

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Jan 9, 2000
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Steve i would just like to thank you for all the hard work you have put in and for giving us the insight into the possibilities of the so called lame cr engine-only one engine i know of has a better spread of power and that took a euro factory over a year of R&D.
 
M

Mike198

Member
Jul 8, 2002
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TMR (Tom Morgan Racing) Has engine mods you can buy $1500 and you get 8 hp over stock. They say its the same there pro team uses. just thought id let ya know that.
 
steve125

steve125

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Oct 19, 2000
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I appreciate your positive feedback, Marcus.

Here's the list of specs for the Dyno chart:
  • fuel is a 50/50 VP mr-2 gas oil mix 28-1 maxima k-2
  • jetting 340 main 25 pilot 2.0 air screw std 2000 yz125 needle 3rd clip
  • intake Delta Valve set on low tension - valve modified for full reed cage view - 2000 cr125 manifold matched to modified valve
  • stock air box with Uni Filter
  • cylinder - all ports measured to stock spec; cylinder lowered .012; cylinder head stock; squish clearance measured .8mm
  • power valves modified per Wes Gilbert's specs (see Rich R indy show pics)
  • power valve stop arm bent for 2mm additional opening of valves when closed; also rear cylinder skirt radiused at intake side for better flow into cases
  • piston standard Wiseco with intake window; standard head and base gaskets
  • ignition - JD from Procircuit programmed to team Plano specs; spark plug BR8EVX
  • exhaust - Procircuit 2000 pipe with shorty silencer
  • exhaust manifold - standard 02 shortened 4mm - works only with the 2000 pc pipe

NOTE: two other pipes to consider that don't require an exhaust manifold modification are the 02pc or the DEP. On the Dyno, they performed the same. On the track, I preferred the DEP because of it's crisper hit. Also these two pipes worked best with the stock timing, the 00 pc pipe used in this dyno chart ran best with a 1mm retard from the std mark. This only applies to the JD ign.
 
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DEANSFASTWAY

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May 16, 2002
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Looks real good steve I like the way it builds power everywhere ,sometimes its realhard to increase the whole powerband . The latest CRs seemed to have a really crappy P/V system to me also I tried a few things like limiters and big ports and had some good luck. but mostly mid/top . those were mostly 00-01s and a few of them we put older mikuni TM carbs on . I have some 125s 144ccs in microsprints with different cyls running on alcohol making mid 40s but they are pretty much mid /top . were also trying some trick jetski carbs in the micros. We also put a RM cyl on the CR bottom end and that thing was a rocket. RMs have big ports and the 96 had booster exhaust ports that made killer top end. Its good to see that youre having some good numbers , it looks as though it should be reliable too since youstated that its not really that radical of a port job or high compression etc. Looks like a well organized collection of components that all work together. A lot of kids these days seem to throw parts at their bikes that look trick and dont work together, I guess thats to impress their buddies or something.
 

steve125

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Oct 19, 2000
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Dean, I tried to get fancy with one cylinder that ended up as a door stop :| In search of more bottom end without hurting the top much. The transfers were matched, the rear boost port tunnel opened a bit, the cylinder was decked .030, and the exhaust eyebrows were enlarged and lowered for more port area. The head was relieved and squish clearance set at 1mm, squish band set at 6mm @2 degrees. Well the power was down big time! The slight gain on the bottom was not well offset by the massive loss from mid to top. These mods just threw the engine out of time. It might have been a different story if we just left the eyebrows alone and raised the exhaust port some.Oh well :think: Anyway as you can see the "stock" cylinder port time area is quite good. It's the intake, exhaust and ign. curve and timing that need tweeking :cool:
 
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SFO

LIFETIME SPONSOR
Feb 16, 2001
2,001
1
Nice work.
What kind of dynojet and who did the runs?
did you run the different tension settings on the reeds?
What are your thoughts regarding the effectiveness of each setting.
Thanks, Bill
 
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steve125

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Oct 19, 2000
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SFO, I go to Pete Payne of HDR for all my dyno runs. He's real good at keeping our runs consistent. The dyno is a Dyno Jet 200. Yes we ran both the high and low tensions and were surprised with a better top end peak with the low tension setting! Neither reed tensions made a difference in the low to mid power over the other, just peak power, not what i expected. :think: I'm sure this will vary from bike to bike though, say a yz set up over a kx ect.....
 

steve125

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Oct 19, 2000
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Ive known of him for years, Pete was one of district 13's fastest experts. But we didn't become good friends untill around 1999.
 

steve125

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Oct 19, 2000
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Joe, Since the ports are all stock in the case of the cr, the ring life is very good. I do a top end about every 12hrs of run time. I've noticed power will start to fade a bit if i go longer.
 

EricGorr

Super Power AssClown
Aug 24, 2000
708
1
Steve and Pete, the powercurve looks great, lots of area under the curve. Great work and post.

I'm interested in the programmable ignition work that PC is doing.

1) What hardware is based upon? IE Vortex, Wolf, Dyna or some other type?

2) Considering that ignition programming software enables changes in ignition timing based on rpm like 5 degrees before top dead center at 5,000 rpm, what areas of the rev range did they advance or retard and why? Was it a change designed to work with a PC pipe?

3) Does PC offer this product and service to the general public and what are the costs?

I got a chance to demo the Vortex programmable software and it was pretty interesting. They give you the choice of browsing and selecting an ignition map from a production bike, back as far as 1990 and for every popular dirt bike model, or altering any of the maps by degrees of crank angle and rpm.
A few years back PC was telling people to use the standard igniter box from a 1995 CR125. Perhaps this is an alternative to buying an oem part and adapting it to modern CRs?
 
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Jman271

~SPONSOR~
Oct 18, 2001
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Hey guys, if your interested in not spending big $$$ on an older CDI & ignition system, there is a complete system for sale on Ebay right now for like less than $20. It says and shows a pic of the CDI, coil, stator, etc,,,might be close enough to the 95 to make a difference. If not, maybe you install it, then fix ports, and mess w/ timing to make up the diff. Anyway, it's real cheap, I know that the Vortex, PC, etc, are a couple of hundered $$$. Type in "cr 125" under search, it will come up. Also, there is a 94 cylinder, head and pv set up on there also for like $30, for under a $100, you could have all the goodies. Although I don't know, you may have big problems w/ PV actuator arms and exhuast pipe mounting,etc,,,? Anyway, great job Steve.
 

steve125

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Oct 19, 2000
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Eric, as far as i know PC does not offer an option for the ign. curve. They told me the curve will be the same one that the Plano team found to be best. They do program it before shipping at Pro Circuit. The gain from the ign. is from around 9500rpm to 11k and is 1hp. It runs the same as stock below 9500 RPM. It apears to have some extra advance starting at 9500, because it peaks a little quicker than stock with a touch less over rev. The ign. is made in Italy i believe by JD, it's the same as used by SRS Racing in Italy. Sponserd riders being Steffy Bau and Jeff Dement. Anyone can order this ign. from PC, just remember you must run a resistor spark plug.
 
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IBWFO

Member
Aug 5, 2001
366
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Not sure if this is the proper place for this but,.........
I am personal friends with the owner of Plano Honda. We are using the Team ignition with a modified cyclinder, Vortex piston, PC pipe w/ shorty. Bike is my son's and he said the improvements were amazing.
Also, the owners son rides a Team bike that uses a totally different cyl/head ( I think a 99)and a special PC pipe, and the bike is incredably fast. Much more so than ours with the current cyl and head.
This leads me to my question. We were waiting for the 03, but can get an incredible deal on another 02. Do any of you think that the 03 will be that much of an improvement over the 02 to warrant waiting on the 03.
Your advice would be greatly appreciated.

D
 

EricGorr

Super Power AssClown
Aug 24, 2000
708
1
I don't know what to think about Honda's 125 development program. I know one guy who develops the engines for the 125 team and he's real sharp, but year after year Honda releases a production bike that raises serious questions.
The best cylinder setup that I've found on this generation of CR125 is the 2000 model. And in the latest MXA they claim PC is recommending the use of the 2000 also.
Personally I think Honda should sack the team that designs and builds the CR125 production bikes and hire people who actually know how to ride 125s. For a company that makes some outstanding bikes, like the 450, the 125 is an embarassment at best.
Best of luck to Honda in 2003, but I'm not holding my breathe.
 
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Jman271

~SPONSOR~
Oct 18, 2001
317
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Did I do something wrong to get my post nuked? If I did I'm sorry, I was just offering up a suggestion b/c there was talk of the 95 jug being the best, etc,,,I saw it on that site for sale, it wasn't my stuff for sale, I was just mentioning it in case any of you wanted to get the older stuff for way less to check it out. Sorry, it won't happen again, regards,- Jman
 
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