Cr Power
- Thread starter gorhen
- Start date
marcusgunby
LIFETIME SPONSOR
- Jan 9, 2000
- 6,450
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If you do a search for 2002Cr125 you will find loads of tuning info
Heres a summary of the best mods to a 2002Cr125
v force reed block
wolf ignition
doma tailpipe
vertex race cr125 piston
lower cylinder 0.5mm and have head modified to not detonate.
If you are handy with a grinding tool you could modify the powervalves like wes gilberts mod in the members photo area(look under Rich Rohich)
Heres a summary of the best mods to a 2002Cr125
v force reed block
wolf ignition
doma tailpipe
vertex race cr125 piston
lower cylinder 0.5mm and have head modified to not detonate.
If you are handy with a grinding tool you could modify the powervalves like wes gilberts mod in the members photo area(look under Rich Rohich)
here are the inexpensive mods:
1. new top end and piston. Inspect all tolerances and fix any problem areas. Be sure the power valves are cleaned
2. 05-07 air boot cr125
3. drill 3 holes in the side of the airbox on each side. These bikes starve for air
4. mxbonz has a pipe spacer that helps out the low end on the bike
5. might as well get the billet clutch basket, inspect the inner hub and pressure plate. Install a new clutch with OEM springs. I run the Tusk brand from Rockymountainmc.com they are like $45 for the bike
6. jetting is pretty spot on from the factory. but adjust as needed.
7. pipe, DynoPort makes one for the bike. They make cone style pipes.
8. vforce reeds
after that, it gets expensive. Big bore to a 134 kit, porting, case mods.
These bikes fly in the mid to top end, especially after the airbox mods. They are soft on the bottom compared to say a YZ125 late model. but top end will eat one up. I am able to keep with CRF450s on the track with mine. I also installed a set of 06 crf250r showa twinchambers on the bike which helps a ton plus pulls the axle back 2mm for increased cornering. A lot of going fast on the bike is body positioning, and keeping your momentum up. YOu will find you take totally different lines on a 125 vs a 4stroke. but they are FUN!
1. new top end and piston. Inspect all tolerances and fix any problem areas. Be sure the power valves are cleaned
2. 05-07 air boot cr125
3. drill 3 holes in the side of the airbox on each side. These bikes starve for air
4. mxbonz has a pipe spacer that helps out the low end on the bike
5. might as well get the billet clutch basket, inspect the inner hub and pressure plate. Install a new clutch with OEM springs. I run the Tusk brand from Rockymountainmc.com they are like $45 for the bike
6. jetting is pretty spot on from the factory. but adjust as needed.
7. pipe, DynoPort makes one for the bike. They make cone style pipes.
8. vforce reeds
after that, it gets expensive. Big bore to a 134 kit, porting, case mods.
These bikes fly in the mid to top end, especially after the airbox mods. They are soft on the bottom compared to say a YZ125 late model. but top end will eat one up. I am able to keep with CRF450s on the track with mine. I also installed a set of 06 crf250r showa twinchambers on the bike which helps a ton plus pulls the axle back 2mm for increased cornering. A lot of going fast on the bike is body positioning, and keeping your momentum up. YOu will find you take totally different lines on a 125 vs a 4stroke. but they are FUN!
if you get one. install a FMF gold series fatty pipe and silencer onto it. that will add a lot of power on both ends. use the best sparkplug like a NGK BR8ES. and always... always! run AMSOIL DOMINATOR 2-Cycle oil. all these will add so much more power. and geared out a cr125 will go pretty dang fast which is what youll want on the track.
hope this answers you question some.
hope this answers you question some.