1998RM250

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Nov 5, 2008
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Hey guys I was doin some reading on power valve settings and had a few questions. The 01' RM 250 has a dual stage powervalve which "mellows" the hit, but is supposed to make good overall power. Is this the only year RM, or should I say bike in general with this type of valve? Also has anyone swapped an 02' single stage power valve in? After getting the bike back from being rejetted again it really rips up top when the power valve opens and hits hard, id say around 5k rpm's. I ride alot of sugar sand and the bike isn't as "responsive" down low as it used to be, but it does run well. Would the power valve opening sooner be better for my riding conditions? I know when it was rejetted he also messed with the power valve settings... Stock setting is 1/4 turn clockwise from no tension, and I think it's at 1/2 turn+ now so less tension would have it opening sooner, but I read online that you can also turn it counter clockwise for a different type of hit? I was just wondering if that was true, or some bogus info?
 

_JOE_

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May 10, 2007
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I played with mine quite a bit on my 02. It made a noticeable difference. A tighter setting moved the hit up higher and made it more violent. A lower tension setting made it smoother but it hit sooner which shortened the lower power bottom end making the midrange a bit stronger and less controlable in the tight woods. Dang, that last sentence even confused me when I read it but that's about the best explanation I can come up with....

As far as dual stage, I haven't seen that before. Does it open the valve partially at lower RPM or operate seperate valves individually? I'd think the tuning ideas would be the same as singal stage.
 

1998RM250

Member
Nov 5, 2008
426
0
Yeah I was wondering as well how they worked, I've never heard of any other bikes having one besides the 01' RM's. Anyone know anything about turning the power valve adjustment counter clockwise, or is that just internet gossip? I'm thinking it might be a little trickier getting the power valve dialed in the way I want it with this dual stage setup.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
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Merrillville,Indiana
The manual is dead nutz accurate on setting, and naming the power valve. Suzuki, heck I even believe THEY have an online access to their manuals! It runs bad yet good off bottom. That sentence makes Joe's perfectly understandable! Single and dual stage power valves, aye carumba. I want the 3 stage! Vintage Bob
 

helio lucas

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Jun 20, 2007
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quite a lot of bikes has them. most of new exhaust valve design (from ~2000 up) are two stage and loads of road bikes. some with two different openings, some with two stage ramps and most with secondary ports area helping the main port.
really some of the designs are not really "two stage" as claimed by manufacturers because they open the area linearly even if linear movement of the valve is "staged" but, who knows??? and who cares??? :nod:
 

1998RM250

Member
Nov 5, 2008
426
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What about turning the spring adjustment counter clockwise, is that even possible?
I guess the pv was just set to open earlier before as it didnt have the "hard hit"
and felt more torquey.
 

_JOE_

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May 10, 2007
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Counterclockwise is simply less tension holding the valves shut. You're turning the seat for the return spring, going in (clockwise) holds it shut tighter requiring more effort from the cintrifugal actuator in the bottom end. Backing it off (counterclockwise) results in less tension making it easier for the crank to push it open. There's no threads or anything on the endcap(piece you turn) just a notch that catches the return spring. Take the two 8mm bolts loose and you'll be able to feel the spring preload increase as you turn it clockwise. It's not going to hurt anything to play with it. Go ahead and experiment, all you need is an 8mm socket and a pair of pliers. I'd mark it with a Sharpie or paint pen before you break the bolts loose so you can put it back where you started if you get lost. :whoa:
 

_JOE_

~SPONSOR~
May 10, 2007
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whenfoxforks-ruled said:
And every year changed the amount of preset, by the book.

This is true. I would imagine they set the PV up to compliment porting changes.
 

1998RM250

Member
Nov 5, 2008
426
0
Right i understand what your saying, but from zero tension can you set tension on the spring counter clockwise too? On another website it said clockwise for mx style riding and counter clockwise more woods riding. Sounded like some bs to me, but I was just wondering.
 


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