I want my powerband to come in at a lower rpm. it comes in at 3/4 qt throttle! 96 rm 125

Hi; It could be A carb or air intake issue, also you power band chip may be bad or your throttle cable may have stretched and is not opening carbs all the way, Check this first before you spend A ton of money like I did years ago. Hope this helps good luck and be safe....

Dirty carb or it needs rejetted.

Hello if your motorcycle is blowing a lot of smoke and oil from the exhaust and running poorly,sounds like you have worn crankshaft bearings or the main seal is bad and sucking transmission oil.

First, do a compression test (Throttle wide open during this)
Make sure the air filter is CLEAN!!!
You may have an issue with...
power valve sticking
crank seal leaking
worn out rings
dirty carburator

i have a 92 rm 250 an i just had it fully rebuilt an it laggs in power band an splutters an feels guttles

The power band is the point wheneverything is nominal and and peak performance is realized. The air/ fuel ratio , timing, rpms It's mor predominant and noticeable in a motorcycle because of handling and weight All engines have them and these "power bands are really the peak of what s also called the torque curve Band meaning sp[ecific point and duration everything is working together. a gas lawn mower engine is set up to run inside this band. Thats why it doesn't fall on its fsce on the first patch of grass.
A diesel engine has a specific rpm range it has to maintain under load to get nominal horses.. If everything is functioning at nominal, max power is put out. Surprisingly enough it can be felt in all engines if paid attention . That's all it is, no special "bands" or parts. Knowing where the power band(range is makes a big difference on any machine. On an electric motor peak torque is @ let's say 1850 rpms. go faster useless lower toyque. go slower power drops To keep the range of the power band constant. everythinhg needs to be constant, like fuel mix, spark plug condition ,air filter andcarb adjustments.. I had a bike I hate and feared the power band. I would fall into it not paying attenyion and it would litterally crawl out from under me. All it is is that narrow band of peak performance..

Probably the "idle speed controller",(the ecu is programmed with target idling speeds values to respond to different engine conditions, coolant temp, a/c on/off etc,sensors transmit signals to the ecu which controls the flow of air through the bypass of the throttle valve and adjust idle speed top target value)
however this what the manual says,
check for defective throttle linkage or cable
check idle up-up vacum switching valve
check coolant temp sensor
check throttle position sensor.
Usually if its major, then the check engine light comes on,

go to bike bandit for all parts.

sounds like you need a new power valve in the cylinder. They can go bad and thats how they will act. You have to take the cylinder off to change it. If your that far you might as well put a new piston and ring in it.

could be. I had a 91 kx 250 that was acting crazy and it turned out to be the stator and cdi box. you can check the stator easly with a omes meter but the cdi box is nearly impossible to check. you pretty much have to buy a new one and try it. also check to see if your power valve is working.