2004 rm125 motor Insights help needed

The 2005 and newer head, cylinder power valves and governor are better setup.

I wouldn't bother with reeds. Stock are good

I am in the process of doing one I will keep you updated. I did the 05 top end with power valve governor. I have had an 04 with just the 05 power valve governor before and that was a improvement alone. I have a 05 cdi I can try it on the 04 but I would imagine it won’t work because the 05 had a power jet. If you can find a factory cdi from 04 i here they are the way to go. I’m currently researching if having a aftermarket cdi programed will be an improvement as from what I have heard is the stock cdi works better than a vortex on the rm if you just use the maps the vortex come with. I tried a v force and stock with Boyesen carbon reeds were way better than the vforce. When I say way better I did not try it on a dyno but I did a test with the stock reeds then I tried the vforce and noticed little to no difference then I tried stock with carbon reeds and noticed much better throttle response and slightly stronger off the bottom. I’m currently trying the rad valve I will let you know how it goes. I’m told I should have the rad valve modified on the rm but I’m going to try it first. If you use a stock carb it will touch the shock spring with a rad valve or vforce. It doesn’t hurt anything but if your a perfectionist it may bother you.

You can do case matching and have your pipe modified to work with your motor mods as well.

This dude named Brody might be able to give you pointers on the RM build.....