how does you know when your powervalves are no good?

[Vector88]

hey guys

how do you know when your powervalves are junk and no good? how often should they be replaced? my viper seemed like she lost a bit of power after the week i had her! cleaned pv's and adjusted the cables with 2.5 mm allen wrench. dont know the problem! anyone?

 

[redsnake3]

either when the cables pull threw or they are damaged by a piston.

 

[daman]

you'll know it when you open it up, it'll be self explanatory...

try a search on power valves or pv, TONS of info to read..

 

[Vector88]

well when i opens it out at full throttle she almost seems like she is on 2 with no powder! but got a litter better today after i went for a long ride! i am after adjusting the pv's a few times now! if each of the pv's was adjusted differently would it cause her to act this way?

 

[redsnake3]

he meant when you open up the power valve casings.

 

[daman]

Oooops yes what snake said,,sorry...

 

[Vector88]

hey ya the cable is still attached to te powervalve so no pull through!

 

[redsnake3]

im thinking that you have a bad set of rings or a piston on the way out, either get a leakdown test done or haul that top end apart.

 

[Vector88]

hey, done a compression test a few days ago and the MAG side, and middle cylinder had 120 psi and hauled about 7 times, and the PTO side was 100 PSI and i hauled about 10 times! i think im gonna re-ring the pistons! that maybe the problem! what do you think? looked in my PV slot the other day at the pistons also and they look real good so i say it is the rings! the motor got 7500 km on it so i think its time to change the rings in it!

 

[Vector88]

woudl that be the problem???

 

[Marker]

Sounds to me like you should get a leakdown test done, I'm not sure that a compression test is accurate on those.

 

[MountainRx1]

Vipers came stock with 110 PTO, 130 Center and MAG. So your compression is 10 pounds lower all across. What elevation are you at?