Northwest Motocross Forum
Big Bore CR125

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https://ewmxschools.com/eve/forums/a/tpc/f/171607236/m/4427051263

Thu October 11 2012, 09:20 PM
Hutchracer
Big Bore CR125
SO I'm getting ready to rebuild my sons 2000 CR125 and I was thinking of doing a big bore on the motor like a 134-144. It would be nice to gain a few extra ponys for this bike. I already have a complete bottom end rebuild kit fro Hot Rods and am looking into having the cylinder done. I was thinking of using Eric Gorr but I was wondering about who does this kind of work local that is quality, not just grinding at the cylinder
Fri October 12 2012, 08:04 PM
joe439
No one local does it and if they did I doubt they could match Gorr's price. Right now might not be a good time to send it to him though they are moving his shop. I'm not sure but the guys on TT recommend Harris Performance a bit also.

I do believe the biggest you can bore that bike is to a 133 the power valve get's in the way if you go any bigger which that model year.

Cheap mod to help the bike is to get the +05 plus airboot it is larger air volume.

I would say you should also look into doing the PWK carb swap it really helps out these CR's.

Sale it and get a YZ Smile I had an '01 CR 125 brand new it was a bitch to jet right I traded it in on an '02 YZ 125 and felt like I was cheating almost looped the YZ the first time out at the old Dairy land of this double jump I had to scream the CR over was cake on the YZ.
Sat October 13 2012, 07:55 AM
Hutchracer
I've heard about the airboot mod but never a year box to go with so I will look into that. As far as doing the PWK mod that is also on the list if I can find one with a reasonable price tag.

My son is the one who rides this bike most of the time and he has never raced just likes to ride for fun so I can't bring my self to getting him a different bike even though I know this generation of CR125 are not the strongest
Sat October 13 2012, 11:15 AM
17dad
Hutchracer, did you get my pm? There is a very good local guy that can help you.
Sat October 13 2012, 06:07 PM
Rays Dad
Fixing up older bikes can be a fun hobby but after riding a newer machine it doesn't seem rewarding enough.