justin1620
Member
Hey fellas, at the end of last season I was leaking oil out of the small power valve gasket. I changed the gaskets this year. Still leaks oil. After taking a look at the powervalve servo motor and revving it up it looks like the pulley is trying to turn once in a while but no consistently. I figured the pulley should be rotating back and forth after 900 rpms. I revved it to about 4500-5000 and it just kind of jerks back about 1/4 of an inch every once in a while and sometimes it wont move at all for a while while the rpms are up. I'm assuming this is the cause of my gasket seals going on me and would this be as simple as replacing the servo and re adjusting, or should i try to re-adjust this unit? thanks
justin1620
Member
by the way the sled only hits 8000 rpms's top, hopefully this is due to the powervalves. Is there any way to check this servo before purchasing a new one?
Skidooslayer687
Member
what happens if you idle the sled below 900 rpms? does the servo "jerk" back and forth? If it does, keep dropping the rpm and the servo will fully open the valves up.
As for testing the servo im not sure, never have had to test one and I dont have my manual handy... If theres a way one of the other guys on here will chime in on how to do it
As for testing the servo im not sure, never have had to test one and I dont have my manual handy... If theres a way one of the other guys on here will chime in on how to do it
justin1620
Member
yes the servo moves when i drop below 900 rpms, but i would like to know how many rpm's are needed to get the servo to cycle so i can tell if the servo is good or not. I am going to try and adjust the valves tonight see if that does anything.
Idling sled below 900 will cause the powervalve servo to go to full open. I'm not sure where it opens on the upper rpms. If you can only rev to 8000rpms pull your reeds and take a look at them. Vipers are known for chipping the reeds. That's why I have 6 spare sitting on the shelf for our 2 Vipers.
Skidooslayer687
Member
If the motor opens below 900 do that, mark it for future use, then adjust you valves, then like SXlover says, check condition of reeds... The servo motor opens I think above 6000 rpm, now i could be way wrong on that but i remember watching it once and see that it was "jerky" in operation as in fast movements of opening and closing while watching the servo when the sled was on a stand. I wasnt having any issues I was just curious as to what rpm it opened at to.