05' Cr125 144 Kit

[Cr85RaCeR607]

Does anyone have experience with a 144 kit on an 05'-06' Cr125. I want to know how they respond to the 144, and how they compare to the other models with 144s in them too.

 

[MXP1MP]

No so far all I have done is just ridden a stock one at most that had an FMF fatty pipe I bet it would haul if done though, since it worked great on the older motors and the newer style motor generally seems to run stronger/better.

 

[robwbright]

While I know nothing about the 05 CR125, I have yet to hear a bad report on an Eric Gorr 144 kit. Virtually everyone has said they're worth the money (including me)! Don't think you can go wrong.

 

[NO HAND]

I believe the cr125 motor 2000 and up can only be bored to 133 because of the cylinder wall being too thin on the exhaust side just above the power-valve.

 

[Cr85RaCeR607]

But i was told that the new egine for 05' can be bored to 144 now. Does anyone know this for sure?

 

[MXP1MP]

No that is correct it can only be bored to 133 the motor is then stroked to get the rest of those cc's. They just add alittle bit to the crank arm length.

 

[Nevada Sixx]

is going up to 133-144 actually noticable anyway?

 

[robwbright]

is going up to 133-144 actually noticable anyway?

Yep! See my post in Forward Motion Forum. The difference is amazing.

 

[Cr85RaCeR607]

So then what would the cost be to bore a CR125 out to a 144. It says $450 on the front page of his site, $475 on another page, and then on the front page it says "price Increase"...So what is the price. Also, since the CR has to be stroked, is that more $ added on top of that cost?

 

[MXP1MP]

It was $475 for the big bore's the price is going up effective 01/01/06 how much I don't know exactly but it won't be no $475 anymore. Plus the cost of the crank rebuild so that might be another $300. It's a bit of a minus with the CR's engine but on a 125 I don't know if 8-10 cc's is going to matter that much really in actual overral power. Now give me a few more weeks and i'll let ya know what my '06 YZ 144 is like :)

 

[robwbright]

Actually mine was $450. From what I've read, the 134 kits make almost as much peak hp as the 144, but its higher up in the powerband. The 144 is more or less for for midrange improvement and the 134 for mid-top.

However, my mid and top are both MUCH better than stock.

 

[MXP1MP]

So I've heard the 133 is suppose to be the better setup for some who spends alot of time in the upper rev range in lower gears. How was your 144 ported? mine is going to be ported for more mid/top. I was going to just mo' betta but heard it was mainly for midrange and took away some of that mid hit.

 

[robwbright]

Mo betta. You can view my first ride report discussing the changes at:

http://dirtrider.net/forums3/showthread.php?t=126800

I was convinced that I was not a good enough rider to take advantage of mid-top, so I went with mo betta - and its exactly that. The difference is amazing - read the link above over at the Forward Motion forum.

 

[Pete Payne]

Yes you can overbore the cr 125 to 144 cc . I have only done a handfull of them . ( 3 ) also did a 3mm over for Steve125 . Maybe he can chim in on it . To 1444 the cr it is tricky you have 2 problems to overcome . 1 - the exhaust port becomes huge if you just bore straight down locating off of the original cyl bore . and 2 - the rear exhaust studd it pretty close to the cylinder bore .

Yes you can also make them rev realy good and make peak HP at 11,000 -11,500 . reliabilty is not an issue when using Eric's pistons.

 

[Cr85RaCeR607]

Pete, so you are saying no crank stroking is needed? Also, my 1st question, how does the CR with the 144 kit compare to the other bikes with 144s. I know that they are a little down on power as a 125, but when it has the 144, would it be the same as any other brand with a 144?

 

[MXP1MP]

That's what he's sayin I like to hear that cause my friend has an '06 CR 125 who really wanted to make it a 144 by just boring it alone but was going to throw down an stroke it also. The $$$ isn't the issue just wasn't real thrilled with having to stroke it he really wanted to make it more of a 150 by stroking it. If EG doesn't do this service when he's ready I'll have to get a hold you pete then! Right now it's the 500AF getting rebuilt so could be awhile.

 

[jmossbarger]

Wiseco will have a 57mm CR125 piston on the shelf in about a month. I spoke to Eric this morning and he said he usually just does the 56mm. 58mm pistons will be available as Wiseco shelf parts for the RM (the RM piston also fits the KTM) and the YZ.

Joe

 

[robwbright]

Wiseco will have a 57mm CR125 piston on the shelf in about a month. I spoke to Eric this morning and he said he usually just does the 56mm. 58mm pistons will be available as Wiseco shelf parts for the RM (the RM piston also fits the KTM) and the YZ.

Joe

Ye, but Eric's 58mm is better and cheaper! :aj:

After all, he designed WISECO's big bore pistons (the ones prior to 2006). They're going their own direction now, apparently.

 

[Pete Payne]

The whole trick is to offset the cylinder bore . No stroking needed . The problem with the cr is the exhaust port gets to be huge when the 58mm (144) bore is located off of the stock bore .

 

[Pete Payne]

By the way , they rip !!