O3RM125

Member
Dec 22, 2007
90
0
Ive never had a power-valve equipped bike before, among other things I mainly rode/raced yz80's from 87-89/90 and I had a couple questions about the power-valve on my 03 rm 125 I got last month.

Far as I understand the valve is open at low rpm, and closed at higher rpm controlled by exhaust pressure, is this correct?

I kinda figured that the action of the valve and the powerband of the engine are tuned to work together in a way. When the valve opens/closes is it something I will/should feel when riding the bike?

I dont see anything on it in the manual, is this valve adjustable? or require any adjustment?

I havent had a chance to really get out and ride the bike much, I dont think its been fully up to temp. either, the couple of times I cruised it down the street is the only riding I have done yet. I went through the carb and verified the jetting is all stock and the previous owner said he ran 40:1 which is still in the tank(manual says 30:1 which is what I plan to run in it), I notice alot of exhaust coming out of the "breather" tube on the exhaust valve(again this is when the engine is cold/barely warmed up), is this normal?

Thanks for any replies.
 
Last edited:

Backslayer

Go Big or Go Home
~SPONSOR~
May 27, 2007
280
0
Im not exactly sure when they open or close, but this is what I know is that, they periodically need maintance, Youll have to clean your exhaust valves, make sure they are set to closed, and your power port is controlled by a linkage that's connected to your governor.
 
Last edited:

xkevenx

Member
Dec 4, 2007
95
0
its closed at low and open at high. if you turn the spring tension up there will be more torq, if you turn the tension lower your bike wil go faster and have its power at the high rpm's. thats all there is
 
Top Bottom