06 CR125 -> 144cc? Cant decide

[O'MALLEY_808]

Hey I traded in my 04 crf250 for a 06 cr125 and I love this bike. Its making me a way better rider and im railing everything. I'm still really fast and competive on this bike but I'm wondering what route to make it a little bit faster, cause with a little bit more power I could be competive against 250f's. I was going to get my bike bored to 144 but I was told the exhaust bridge would be very small and may expand more than usual causing it to rub on the piston. Are the 144cc kits reliable? I was thinking of keeping standard bore and going fully ported and polished with a milled head and race gas.

What route should i go? This thing is wide open everywhere!

Thanks

John

 

[MXP1MP]

I would go the big bore route :) the largest you can get an '06 CR 125 is now that wiseco has a new 139 piston it's fraction smaller then a 144 not much power difference. I would do that and the porting and head mods re gear it so far i'm REALLY liking the 14 tooth up front on my yz 144. My friend has an '06 CR 125 this will be definetly one of his next mod's I'm thinking he's waiting for EG to start up again he really likes mine. If you think it's fast now :) I'm dying to see what it's like when he finally gets it done it's gonna rip!

Mine has been reliable and I do still rev it up but not as high most of the time now it makes more power earlier. I think someday we'll put his CR motor in a CRF frame and maybe do something like add an bleed off vent hose right above the RC valve on the left side. It's the new 2008 :)

 

[robwbright]

144s are great. It's worth the money. Reliability is great thus far.

 

[Pete Payne]

You can big bore the CR to 144. The 139 is a 3mm oversize , the 144 is a 4mm oversize. In my opinion the CR can go to 144cc ,I have built a few, you have to offset the cylinder bore from the original centerline . This is done so the exhaust port does not raise up too far. They run great . You could use Eric's piston , they work well in the CR's.

 

[MXP1MP]

Pete I have a friend that has an '06 CR 125 who is wicked jealous of my '06 YZ 144 eric built me. HE really wants to make it a 144 in the very near future (next few months) here. How can I get a hold of ya to find out how to get it done.

 

[Pete Payne]

hdr81@verizon.net

 

[beamer101]

about how much does it cost to get the 144 upgrade. i have a 2002 cr125