My 02 CR155

Tumic
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Sundsvall SE
Edited Date/Time 9/14/2013 12:22am
Hi!

Thought it was time to post my bike up here and ask som questions at the same time.

CR155 02









Engine:

*02 bottom end
*SRS racing 1th gearbox sprocket
*Eric Gorr stroker 58.5mm
*99 HPP valve Eric Gorr Cylinder 58mm mid/top porting
*Milled cases to clear the stroker crank/ rod (not the piston skirt)
*99 Eric Gorr head for racegas
*GMX radiators

Air/Fuel

*Boyesen radvalve.
*38mm YZ125 carb
*07 cr125 airboot
*Run 50/50 Shell Vpower/100LL fuel
*Twinair filter/alu cage

Ignition:

*01 CR 125 strator/flywheel
*01 Pro circuit/JD cdi box (stock PC curves)


Exhaust:

*02-03 cr125 Pro circuit works pipe.
*02-07 cr125 Pro circuit R304 shorty


Suspension:

*Kayaba Forks, coated and modified by Mansson suspension, swedens Enzo techninca guy.
*Kayaba A kit works shock.

Brakes/Wheels:

*Motomaster oversize front
*Stock rear
*Excell/HAAN A60 whels

Clamps/Bar:

*Twinwall 997
*Sunline clutchperch
*Stock clamps

Plastics/Graphics:

*Ufo plastic
*Cycra front plate
*TJ Retro kit.


So about the bike, im not super impressed with how it runs, when i search allt the forums, 99.99% are pretty happy with Eric's engine works, but i think my bike would be stronger than what it is at the moment.
It feels kind of flat, pretty mellow on top (i know it will be a bit shorter powerband with the stroker, but it feels so weak down low to) the stock -12 KTM sx125 outperforms my 155 bigtime down low.

But after xmas/new year i will get the bike up on the dyno and get it properly jetted and a new igition curve for the 155cc kit insteat of the 125cc kurve i've got now, but im looking for somee more mods to the bike before i go there.


So.. som questions then..

1: Exhaust? i don't think the PC set-up is the ultimate so im looking in the DEP 144cc pipe, but they only make those for 05-07 so im gonna borrow a 06 stock pipe from a friend and see how far off it is and how much work it would be to get it to bolt on.

2: Exhaust nr2.. i saw something in a couple of threads in different US based forums that some guys run KX 125cc pipes? does anyone got a picture of the kx pipe mounted up on the bike? or more info then "i've made it fit with my gigat hammer"
im banging my head against the wall on what i should do to get some more speed out of the bike (please, no pictures of 500cc engines or "buy a 250cc" i got both of them in the garage allready) but im a bit curious on the KX setup, and if i go that way it will probebly be a HGS or DEP KX 144cc pipe

3: My airbox is still undrilled, but i will get to that before the dyno time.

4: Reedspacer? god or shit?

Any inputs/good advices on the build? Got somee more parts incoming that i will post when i get them,
Sorry for my bad english.
//Jesse Westerlund - Sweden
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suzuki rider
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Manhattan Beach, CA US
11/27/2012 8:27pm
I wish I could help, I don't know enough about bikes, but I'm interested in what you mean by drilling the airbox? Is that some technical thing or is it literally just drilling holes in it?
Tumic
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Sundsvall SE
11/27/2012 9:55pm
It's just drilling holes in the airbox, the older cr125 lacks a bit of top end due to the bad airflow, so when you switch to the 05-07 airboot and drill some holes in the airbox it will perform vetter on top.
Jakes Dad
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Brooksville, FL US
11/28/2012 3:14am
1st check your squish, have heard his machining practices are suspect. Sounds like to wide of squish gap and low compression ratio. Too many people take for granted that their stuff from a big name engine builder should rip your arms off. I think these builders need to provide a spec sheet on things such as where squish is set, squish band width and chamber volume. Then dyno the motor "to prove" it is worthy of the money you've spent.

By the way my guy does.
www.tdc2strokeperformance.com

PS those "kits" aren't all they're cracked up to be, from any builder.
Tumic
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Sundsvall SE
11/28/2012 3:33am
Thanks for great input! The engine guy that shall dyno my bike said the same thing about the squish band so i will check that after work tomorrow.

I also got a reply from HGS that they have a cr144 02-04 pipe but it's a special order and it's not in their regular parts catalog.
So i will turn to my swedish HGS distrubitor and order a pipe from them.

The Shop

IceMan446
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Sacramento, CA US
11/28/2012 8:47am
Jakes Dad wrote:
1st check your squish, have heard his machining practices are suspect. Sounds like to wide of squish gap and low compression ratio. Too many people take...
1st check your squish, have heard his machining practices are suspect. Sounds like to wide of squish gap and low compression ratio. Too many people take for granted that their stuff from a big name engine builder should rip your arms off. I think these builders need to provide a spec sheet on things such as where squish is set, squish band width and chamber volume. Then dyno the motor "to prove" it is worthy of the money you've spent.

By the way my guy does.
www.tdc2strokeperformance.com

PS those "kits" aren't all they're cracked up to be, from any builder.
Jakes Dad you seem to plug TDC quite a bit, I have a couple of questions for you if you don't mind:

I am considering getting the 144 treatment on my 04 YZ125. But I want something that I can run half pump and half race gas. I don't want to have to run straight race if I can get around it. I don't make many changes to my bike right now as far as jetting goes just because it runs so crisp in the winter or summer months, but I would like more power through all the RPM range. I ride mainly moto but I also will ride trails and offroad stuff. I have heard horror stories of jetting issues and trying to get their bikes to run right.

Also, if I go with TDC what do they recommend as far as pipe and silencer combo and brand of replacement top end kit? I checked their website out and they didn't have any recommendations for that stuff as far as I could tell.
Jakes Dad
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Brooksville, FL US
11/28/2012 1:12pm
Iceman just call Brent, he may not answer if he is machining something but will return your call quickly. Brent built a 150cc RM motor it runs on 50/50 big problem he had was the clutch holding, it slipped. They got a new clutch and had to set the seat pressure of the clutch springs a little higher for it to hold. Kid rode it in 250B and battled for wins all the time.

The cool think with TDC is he can set up cylinder heads 10 different ways to better suit track conditions and your riding style. And of course what octane you plan on running, everything is run through computer programs that tell him where things need to be and he machines it up.

And then the bullshit will stop with other builders "claiming" their hp numbers, Brent will dyno the motor (you get the sheet) and have it setup to put in the bike and race.

Brent is a motor builder not a website designer he cares more about strong motors and happy customers than a flashy website. He's also on facebook.

http://www.facebook.com/TDC2StrokePerformance?ref=ts&fref=ts
IceMan446
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11/28/2012 2:04pm
Jakes dad...Cool man appreciate it. You seem like you have had good success with his work. When the time comes I will have to pony up and get it done right.

Thanks man.
mx5471
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11/28/2012 2:29pm
Jakes Dad, I've talked to you on here before. Can TDC bore a cylinder? My son blew the top end on his 125, our fault, He reems it and we should have done the top end. Next ride the piston cracked and blew the jug. Can they do a 144 on it? The cases are already ground as we had an Athena kit, (junk), on it in ,07. I'm in south Georgia. Where are they located?
Jakes Dad
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11/28/2012 5:41pm Edited Date/Time 11/28/2012 5:42pm
Yes he can, best to bore it have him port it (adjust port timing to bigger bore). Then send off to be coated. He is in IL 2 days shipping usps flat rate boxes are pretty reasonable.
HenryA
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Stockholm SE
11/29/2012 1:45am
Where did you get that suspension? And how well does it perform? It surely looks nice. And so does the rest of your bike. Good job!
Tumic
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11/29/2012 2:28am
Thnx!

The work was originaly done by Racetech in Holland 02 (this bike is a former GP bike from Care/Donjoy Honda in Holland, so the coating etc was done by them.
Then Månsson rewalved it for me 2010, but the springs are to soft for me.

I bought the new KYB rear shock two weeks ago from a guy in gothenburg, but i also have a KYB A kit fork that in trying to buy with the right springrate.

We got a 03 cr500af that will get my current suspension if i can get the KYB parts for the 155cc
Frodad78
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11/29/2012 5:32am
Awesome bike man. I've been building up an 01 CR125 for the last year now. I'll I've been able to find is a 134 kit. Pretty impressive.
Tumic
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11/29/2012 5:52am
Thnx dude!

That is why i run the 99 cylinder/head combo cuz you can bore them to 58mm (144cc) instead of 134cc (00-04 cylinder)
Frodad78
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11/29/2012 8:55am
I see..someone has to do the case work as well right?
Tumic
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11/29/2012 9:13am
For me there were no clearence problem with the pistonskirt/cases.
I had to mill the bottom of my cases due to the stroker crank, so 144cc big bore did not require any case work for me.
Frodad78
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11/29/2012 10:16am
Ah, so the bored over 99 cyl just bolts on? Is the powervalve setup the same?
Tumic
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11/29/2012 12:29pm
The cases on the cr125 is the same from like 91-02 i think, 00-02 got the new powervalve setup = 134cc Max.
But you can fit the old HPP cylinder on the 00-02 cases along with the older powervalve guvernuor or what you guys now call it (the thing that controls the valves down in the engine cases, hope you understand my bad english :/
Tumic
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11/29/2012 1:09pm
Guess it's official now then, this is the new fork, currently in Belgium at KYB Technical-touch, bought it straight from them (used condition) and they will revalve it for my specs and springs for my weight.



Cant WAIT to get it on the bike now!
mx5471
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11/29/2012 4:27pm
Jakes Dad. Does TDC just do the cylinder bore and port work, and then I need to get it plated and the piston fit, or does he do it all? Millenium is up there and they do good plating work. Does he use them, or send the jug back ,and you get it done? Thanks
Jakes Dad
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11/29/2012 5:02pm
He'll send it off and then do a final clean up of the ports after the plating. He's very anal with the blend area where the rings pass by the port edges. Extra time there means many more hours of ring life. My 17 to 1 supermini motors dropped 10% compression at about the 20 hour mark. Time to check piston and change rod bearing anyway. When you hear people say they're changing rings at 6 to 8 hours it's because of poor attention to the blend area of ports.
Tumic
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11/30/2012 7:55am
I've messured the squish angle now and its about 1.9-2mm or in US terms = 0.0787401574804 inches, i don't know whats normal but in Eric Gorr's performance handbook he recommends 1.5mm to the regular 00-03 cr123 cylinder/head combo.

Any thougts?
slipdog
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11/30/2012 9:02am Edited Date/Time 11/30/2012 9:02am
Tumic wrote:
I've messured the squish angle now and its about 1.9-2mm or in US terms = 0.0787401574804 inches, i don't know whats normal but in Eric Gorr's...
I've messured the squish angle now and its about 1.9-2mm or in US terms = 0.0787401574804 inches, i don't know whats normal but in Eric Gorr's performance handbook he recommends 1.5mm to the regular 00-03 cr123 cylinder/head combo.

Any thougts?
Normally between 1-1.5mm(.040"-.060") for best performance. The tighter the better, but you never want to go under .030". At almost .080" you have way to much squish clearance.

Just to be sure, did you measure the piston to head clearance at TDC(correct) or how deep the squish band is cut into the head(incorrect)?
Jakes Dad
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11/30/2012 9:17am Edited Date/Time 11/30/2012 4:07pm
Squish should be around .035 ooops didn't see the above post. I had mine at .032 in one motor but found when big end bearing failed piston slightly touched the head. So I use .035 for me.
Tumic
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11/30/2012 9:50am
Sounds like Eric Gorr fucked up big time on this one then..
Tumic
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12/1/2012 12:27am
You got a pm..
Tumic
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12/23/2012 8:54am
Some images/spec's


















I've also contacted HGS exhaust in the Neatherlands and they told me that they have a 144cc pipe for 02-04 Cr125 but you have to custom order it from your HGS dealer, so i will probebly run a HGS exhaust.

Im thinking on trying a new silencer to, the 304R seams to gice it a bit short powerband.
Tumic
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12/23/2012 10:45am
Some more pics.. Pretty awfyll missmatch on the cases/cylinder



BAMX
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12/23/2012 5:27pm
Tumic wrote:
I've messured the squish angle now and its about 1.9-2mm or in US terms = 0.0787401574804 inches, i don't know whats normal but in Eric Gorr's...
I've messured the squish angle now and its about 1.9-2mm or in US terms = 0.0787401574804 inches, i don't know whats normal but in Eric Gorr's performance handbook he recommends 1.5mm to the regular 00-03 cr123 cylinder/head combo.

Any thougts?
slipdog wrote:
Normally between 1-1.5mm(.040"-.060") for best performance. The tighter the better, but you never want to go under .030". At almost .080" you have way to much...
Normally between 1-1.5mm(.040"-.060") for best performance. The tighter the better, but you never want to go under .030". At almost .080" you have way to much squish clearance.

Just to be sure, did you measure the piston to head clearance at TDC(correct) or how deep the squish band is cut into the head(incorrect)?
I agree about never going under .030 for that size piston. How again did you check the squish? solder, measuring etc...If you used solder, your technique makes a big difference.

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