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2-stroke power valves???

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So I have this 09 KTM 300 XCW which I installed the red spring in, which gives the powerband a bit more 'hit'. I read on these forums you can remove the red spring for an even harder hit. It this true? Is it recommended? Will it hurt my bike? Pros vs. Cons?? Thanks!

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my personal opinion is that the yellow and green springs delay the powervalve opening so you have mellow power down low and than it hits hard on top, I like the red spring with the preload adjuster backed out flush with the case, this seems to give you a strong hit down low, but i have a 250sx and ride mx and I am still not done playing with it-good luck

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Yes, I understand what the springs do, but I read one reader took out the colored spring. Is that OK? Also what does the preload adjuster do. I was told not to mess with it.

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Go ahead and play with the preload. Just be gentle. The springs change the rpm that the pv will completly open. The sx will hit different then the xcw cause of the motor. Change this with porting. I am not sure about removing the spring. I think you would need to take both out to be safe. Then the preload adjuster would be useless. The pv would probably open completly pretty early. I wouldn't do it, but I have had some pv spring issues as of recent and I am kinda weary of touching the thing.

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definitely want to leave the large spring in at least. won't hurt to experiment with no inner spring, it's just a fine tune adjustment. The larger spring carries the bulk of the load. Now if you could get lighter and stiffer outer springs, then you could really change the power delivery.:)

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definitely want to leave the large spring in at least. won't hurt to experiment with no inner spring, it's just a fine tune adjustment. The larger spring carries the bulk of the load. Now if you could get lighter and stiffer outer springs, then you could really change the power delivery.:thumbsup:

Is the large spring big enough to not fall out or get jammed somewhere? I am still nervious because of what recently happened to me.

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definitely want to leave the large spring in at least. won't hurt to experiment with no inner spring, it's just a fine tune adjustment. The larger spring carries the bulk of the load. Now if you could get lighter and stiffer outer springs, then you could really change the power delivery.:thumbsup:

I believe you can get a lighter outer spring. Saw a post about it somewhere.

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Is the large spring big enough to not fall out or get jammed somewhere? I am still nervious because of what recently happened to me.

yes. it's what holds everything in place. the inner spring is just a fine tune adjustment and not really needed in a design aspect.

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