97 rm250 help please

[schwabdale]

I have a 97 rm250 and am at a loss.
Reeds, power valves, air filter, jetting, packing, gearing, 32:1,
Cinnamon brown spark plug. However, I still have just a little hit on the bottom, and nothing at top, it just flattens out. I have not checked the nikasil, or the compression yet. Over the last couple of years, I have replaced the top end 2 times. Since I bought this bike, it has never had any real power. I also have an 01 cr250. The RM is not comp. to the CR. I think they should be.

Three questions,
1. Is this how the 97 RM250 ran? Can someone tell me how theirs runs?
2. Does anyone know what the compression should be if I use a compression gauge?
3. Am I missing something I should be checking?
4. How much power does a port and polish add?
Thanks for all the help.

 

[_JOE_]

Have you removed the PV cover and started the bike to see that the actuator is pushing the valve open? Does it run smooth and weak up top or does it break up? Sounds to me like either a PV or main jet issue. It's also possible that you could have an ignition problem, but I would keep that on the back burner as a last resort.

 

[schwabdale]

No, I did not remove the cover to see the valves move. However, on the side of the engine, I can remove a cover to see the pv move up and down. I took the exhaust pipe off to see if the ports are opening when the valve goes up, and they are. I checked the timing, it is good. I thought the same thing about the Main Jet, but I have tried so many jets, and nothing seems to change the top end power. I don't think the power valve is working perfect, but, it is opening and closing. The reason I say not perfect is because when you turn the throttle, its does a little bit of bouncing up and down.

 

[_JOE_]

You need to verify that the actuator is moving while running. Just brcause you can manually operate the PV doesn't mean it's working. How can you tell that it bounces when you give it throttle?

 

[KeithKDX]

I have a 1996 rm 125 and i had very simular problem with my bike after i got it rebuilt there is an armature on the bottom and top end with a rod that connects the two to operate the power valve check to see if both sides are together and that the clips that hold them in place are still good cuz if not it will slip off. Another thing you can check is if your power valves are seated right and hell if you take them out go ahead and take a wire brush to get all the carbon build up off of them

 

[anthony96rm250]

got a 96 rm 250 got great power stock piston and fmf tubrine core 2 silencer and runs good