Power valve motor cooked ?

srx70024

srx70024

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Joined
Sep 9, 2004
Messages
132
Age
53
Location
Westfield, MA
I hooked up my power valve tester from Maxx perf to my lawn tractor battery and it didn't really do anything. The spindle kind of "twitched" a little bit, but did not open the power valves at all. Had a good connection to the battery and the the ignition switch was on.
Is this an indication that the pv motor is no good ? Is this a common failure?

Anyone got one for sale ?

Thanks
Matt
 

valves

I've already had the valves out and they looked good. It's only been about 300 mi since they've been cleaned.
 
Pull the cover off sevo where the cables go in and turn the motor by hand and pull on the cables to see that they are all free :rockon: :rockon:
 
Mine did the same thing , i would keep trying it because i get mine to work when it does that .. try moving the servo motor by hand so you get a little slack in the cables then try it again , if it still just twitches , try putting the pipe back on and start the sled and run it for a sec. then try the tester again , you should also be able to feel the edge of valve , try to adjust by hand and feel if the valves are moving , if not ,there stuck... good luck .. i think if you play with the tester alittle you will get it to work ...
 
Another good method (I don't have a tester anyway) is to take the cover off the motor, start the sled, idle it down under 900 rpm and watch the valve motor rotate. Once it rotates, hit the kill switch and mark the position of the motor with a marker. This is then the position that the tester would have cycled the motor. This easy method is why I didn't buy a tester. Plus this will show you if the motor is working or not.

Jon
 
Valves

Thanks everyone for the reponses. I had the valve out and they are not stuck. I put them back in and was able to move them up and down from within the exh port, so I don't believe it is the valves.
I also did like B2SO mentioned, with the valve connected, turn the motor and the valves were pulled up without any problems.
I'll try some of the above mentioned methods.

Thanks again.
 
Last edited:
Put the rear of your sled up on a stand so that you can spin the track some. Remove the black cover on the powervalve motor and start the sled and let it warm up properly. After that just give it a few quick hits of the throttle to see if the powervalve motor is operating or not. Put a mark on the servo pulley so you can see easier exactly how much or if it is moving. Also when adjusting or removing the powervalves I recommend starting and warming up the sled first. The vavles will slide easier when the oil or any carbon deposits on them are warm making them easier to adjust or remove!
 
troubleshooting

Ok, I'll troubleshoot the motor according to the tech page and see what happens.

Thanks Spec, I'll give that a try.

How do you determine if it is the CDI? That's an expensive part to just replace without being 100%.

thanks.
 
I check for resistance in a good CDI from the power valve cable and then with the bad one and found a few dead shorts in the cdi that should not be there and wa la...bad cdi :)
 
I took my power valves out and cleaned them, they were gummed up bad, once cleaned I put them all back together with a thin coat of oil so they moved real smooth. Anyway, I put the tester on them last night and it would turn the power valve motor till it pulled the cables tight and then started twitching, but I don't think it opened them, I am going to pull the exhaust manifold off tonight so I can feel if they are open or what. But I am wondering about this CDI theory? I am going to check my resistance with my dads viper and see if there is any difference. :o|
 
Problem

Kuku - What was your sled turning for RPM's ? Did you notice any loss of RPM's ?

I had noticed a loss of R's at the end of last season, that is what prompted me to start looking into this.
 
Actually I thought it run good. I have over 3500 miles on it so I thought I should clean the power valves, now that I seen them I am going to clean them every year. But it sounds like I am having the same trouble with my tester that you are and I am wondering if they weren't even working last season.
 
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