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RM125 Powervalve?

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A friend of mine makes his so it sticks open, he says it goes faster, and now the top end is blown. Did it have anything to do with the powervalve stuck open? Thanks.

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i doubt it, the powervalve only effects the timing.

what do you mean by "his top end is blown"? did it grenade?

how does he know it was the powervalve? it could have been something else such as ignition timing was off, or a loose flywheel

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i doubt it, the powervalve only effects the timing.

what do you mean by "his top end is blown"? did it grenade?

how does he know it was the powervalve? it could have been something else such as ignition timing was off, or a loose flywheel

Well, I'm not sure that the powervalve did it, I was just wondering. Not really blown, but the cylinder/piston is all nicked and scratched, and it wont crank.

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I'd call that blown. That is usually from a worn top end and not likely to be powervalve related.

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he either siezed it from running too hot or lean (not the powervalve), or he didnt mix his gas.

it could also be the lack of warming up and just givin'er, OR if its just scrached then it could have swallowed a spark plug electrode.

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to my knowledge the power valve partially closes the exhaust port to give greater back pressure for better low end power??? am i wrong?

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to my knowledge the power valve partially closes the exhaust port to give greater back pressure for better low end power??? am i wrong?

yes, you are wrong (kinda). the powervalve is a quarter moon shaped plate that rests on the top of the exhaust port. when the engine hits a certain rpm the plate slides back which advances the port timing. advanced port timing yeilds more top end power, and retarded timing (later timing) gives better bottom end power. get it?

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right...ok.....i am wanting to learn about 2 stroke motors...like alot....i dont understand port timing and such......i have a million questions.........know of any online 2-stroke 101 type sites? but not just 2 stroke cycle but more indepth

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I have a 97 rm 125 and the exhaust valve was sticking so I turned the spring backwards to keep the valves open all the time. It made a huge difference in the power mostly the mid to top. I really didnt feel that I lost the bottom to much.

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I have a 97 rm 125 and the exhaust valve was sticking so I turned the spring backwards to keep the valves open all the time. It made a huge difference in the power mostly the mid to top. I really didnt feel that I lost the bottom to much.

That is so ghetto!

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