power valve problems need help please

brasshole · 01-15-2012, 11:03 PM

ok here goes the story, i just got a 07 144 sx, really clean bike. the guy put a new top end in it bout 2 hours on it, but heres the deal i got the bike home took it for a ride and it was a total dog, goes nowhere, may b a top speed of 45-50. the gearing is stock and everyone tells me this thing should rip.. so the only thing i can think of is that the power valve isn't kicking in,

Jason380mxc · 01-15-2012, 11:39 PM

I hate to state the obvious. PV issues would usually be 1 of 2.
1- PV closed and doesn't open equals great low end with no top end.
2- PV stuck open equals no bottom end with greatl top end.

brasshole · 01-15-2012, 11:46 PM

well then this thing has NO top end at all, I'm guessing the PV isn't in there correctly or the timing is off, is there a way to check this all out without having to take off the top end

bajadog · 01-16-2012, 08:42 AM

See if this video helps...

http://www.youtube.com/watch?v=XTciYyryJuM

tye1138 · 01-21-2012, 01:46 AM

Its very common with these motors to put the head on and miss the little pin that actuates the power valve properly. So first thing I'd do is expose the inspection plate and look in their with a flashlight. There is a little C and a pin that sticks into the C. Per the video above you can see the little C and the pin comes out of the motor. I'd bet you thats the problem...

brasshole · 01-26-2012, 11:29 AM

OK this story gets really good.... and sorry its long

so i ended up taking the bike to a guy to rebuild the forks and as it was there i thought hell have it for a few days so might as well get him to hook up the power valve while there plus he wasn't gonna charge me that much. so he calls me and tells me that the bike has big issues, he says he took off the head and attempted to hook up the power valve and it still didn't work, he says the centrifugal gears that engage the power valve are stripped out and that the power valve arm itself it jacked up and it would be 890$$$ to fix it. so i basically told him no thanks and that i was gonna pick the bike up. so i got the bike back home and pulled the head hook up and re timed the power valve and the bike runs perfect may b a lil rich still. so i call back the mechanic last night and he's like I'm glad you picked up the bike cause that was a expensive job it was a great idea to give it back (i told him that the guy i got it rom was taking it back), so i tell him that i put it all back together and it works perfect he immeaditally says no way so i say YUP it runs like a beast, he then says let me call you right back, and needless to say i haven't herd back from him....

so those of you in houston..
STAY AWAY FROM DNA MOTORSPORTS. HIS NAME IS DAREN TERRY, SAYS HES AN AMAZING RACER.
HIS NUMBER IS 832 258 8354

tye1138 · 01-26-2012, 09:56 PM

So he just doesn't know his elbow from a dirt bike does he! WOW, I mean the KTM power valves are pretty indestructible. He musta just been confused on how it works, that happens... which is why I learned how to fix'em myself!

Good story though, happens a lot I bet.

gmoss · 02-05-2012, 08:00 PM

Well, a brand new timer is expensive, but not that dern expensive!

BTW, if you do need one, I have 2 of them for a 125/144.

... and they will be a steal compared to that guy. hahaha