need help with my rm125

[03blasteryfs03]

i got a 2002 rm125 with boysen reeds, bills pipe, and a new airfilter and that is about it for engine mods, this things realy rips but i have notice when riding got on my cousins 03 ktm 125 sx it has i guess more top end feel like pulling power could it be the power valve adjuster and where should i set it or should i search somewhere else

 

[fioz600r]

do you mean the ktm has more power or more topend

 

[03blasteryfs03]

just feels like it revs more i guess like it stays in the powerband through gears and like has just more topend and a bunch of peaple say my powervalve adjuster is to retarded i am a 2stroke wiz but just dont no alot about the powervalve

 

[liljatownboy]

jetting is were its at. my yz 125 stock jet was a 350 i went down to a 290 and the thing has power like no other but be carful of jetting too lean

 

[92blaster]

i didnt know you could adjust them on that model.. is it a barrel type power valve??

 

[worst nitemare2]

powerband falling off is alot of the time caused by old reeds. to an extent, its a ktm, ktm's have incredible power they are called a cheater's 125, but sh*tty handling.
the powervalve is set from the factory and thats where it needs to be.

 

[4cfed]

the ktm is a faster bike by far.. . thats the answer to your question... the 250 ktms are just sick!!

 

[03blasteryfs03]

my dad funked with it and it is like a 3 half moons one on each side and one in the middle i beilve but my bike is faster than the ktm but just doesnt have the power to rpm like the sound u hear from a 125 just stays up in the rpm mine goes dwn in rpm then back up i dont know its probly just me

 

[fioz600r]

Well from what I understand adjusting the power valve will just move the power to a differant RPM no HP gains

 

[4cfed]

my old cr125 was old school atac set up.. and it stayec 'on the pipe' even i shifted... pulls like a ape

 

[worst nitemare2]

you should really keep the setting how it was from the factory, the powervalve is used to increase/decrease port timing throughout the bottom end, when your in the powerband the powervalve is open, messing with the setting is only going to hurt your bottom end. it will have nothing to do with your bike at WOT

 

[92blaster]

i thought the quadracer was the only one with adjustable pv's.... correct the adjustable pv's dont add power they just move the rpm back to help you go into the pipe more smoother (at least this is how it works on the quadracers)
my old YZ just kept going never fell off the band ever..

 

[liljatownboy]

mybe you should lighten your flywheel or get the weight to make it heavier

 

[fioz600r]

Adjusting the power valve will move your power to a differant rpm. no horse power gains

 

[03blasteryfs03]

came to find out there was a bind iin the trottle cable so it was pulling about 3/4 thootle and now it fing rips haha i thought it had more power when i 1rst got it theres the answer hah thanks guys

 

[fioz600r]

came to find out there was a bind iin the trottle cable so it was pulling about 3/4 thootle and now it fing rips haha i thought it had more power when i 1rst got it theres the answer hah thanks guys

LOL so you never got full throttle?

 

[liljatownboy]

did you just ride it this late at night

 

[worst nitemare2]

Adjusting the power valve will move your power to a differant rpm. no horse power gains

it wont actually move the powerband it can just lead to a much more useless bottom end which can make it feel like the powerband is in a different spot.

in theory it can be like a hose, think of a garden hose, at low pressure, if the opening is closed to an extent, the pressure gets much greater, but when the pressure increases to a point the close in the opening is only retarding the flow, so the opening is released as the pressure gets higher which leads to a very quick achievement of full pressure (WOT) and pressure (power) at low pressure (RPM's) however do not use that as a bible, there is so much more math to it than that, it is all port timing.