sx viper power valve action

Thanks again guys, I'll keep you informed of the continuing saga. You've kinda put fears to rest about the humming. and you're right, when I first start it, it's revving kinda high. Then I give it the gas a little and you can see the servo kick around and the idle drops down nice and smooth. What a machine!
 
Well, I'm back. Have you ever seen that add on TV with guy sitting in front of his PC all night and the last screen says "YOU HAVE REACHED THE END OF THE INTERNET" ? Well that's how I felt last night when I finished reading all the threads about power valves on TY. I still see something missing (maybe my blurry eyes just missed it. I feel certain I;m not the only one still a little mistified about the servo action. I would think someone would have drawn or written a little timeline showing servo position at "key on" , servo position at "start up", servo position after a quick rev when it settles down to low idle, and what one should see through the tach range. Am I being too anal, or do you think this would be of value to others.
I just got home from work and went out to take some pictures to try and analyze this and I don't think it acted right. Here's what happened. I turned the key on and the servo didn't move-it just hummed. I started itand the servo turned clockwise lowering the valves. I gave it a quick rev to knock it down to low idle. The servo went counter-clockwise when I revved it then back clockwise when the idle settled down. After that, if I rev it again the servo doesn't move. Shouldn't it be moving like above 1700 RPM or is it much higher. I posted three pictures: 1. squeaky clean valve
2. servo at key on
3. servo after engine starts

The servo did not cycle when the key was turned on.
Thanks for baring with me on this. I think a lot of us would like to understand this activity and what is correct.
 

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Rev the motor up to 6-7000 should see the servo pull the valves open(CCW) then go back to closed pos.(CW)when rpms come down

post back telling us if thats what happens..
 
Bob, to get so worked up about how it is all working....make sure that the valves open when you get it to about 6000-7000 like daman says and see what happens....to much thinking and your head is going to start spinning.... Are you sure that they are adjusted to spec...on my first powervalve adjustment, I over tightened them and pulled one through. Just double check your slack in the cables start it up and make sure they pull around the 6 to 7 mark!! Go from there!!!!!!
 
Hey guys,
I'm back! The guy thats so anal about the servo action during acceleration.
I had to replace one of the cables and now I'm pulling the carbs to clean them (bogs down just coming off idle). Getting back to the servo action for another second, for the whole 1st year I owned the SX, when I turned the key on I heard the servo go "zip zip" like it was cyling. Do yours do that and is that correct or could that have been caused because I had a stuck valve. The reason I ask is that it doesn't do that now. Even if I have no cables attached to the servo, the wheel doesn't move until the engine starts. Earlier in this thread I posted pictures of the wheel position with the key on and with the engine started and at idle. Do they look like one would expect?
Bet you're sorry I'm back, huh?
 
There is certainly plenty of info on the subject and plenty of knowledge in this forum. The instuctions in the tech pages and the many threads gives you all the info you'll need. I just have these last few nagging questions to answer before I'm satisfied that everything is OK. It just seems anyone with a Viper would hear if the servo zips back and forth when the key is turned on.
Mine always used to and now it doesn't. I'm just trying to establish which is correct. Sorry, it's just the engineer in me.
 
i understand how to remove them, and then adjusting them im a little confused. If i have the motor below 900 RPM the servo should shut all the way correct? then how do i adjust the cables? I understand how to tension them but at what point am i adjusting them to?
 
Hey Bob,
I just bought an 03 Viper for this season as well. It has 2700 kms (1680 miles) and nothing has been done to it. At what milage should the valves and carbs be cleaned at? I know the guy put Seafoam in the gas tank to winterize it but thats about all I know. :letitsnow
 
SX Bob said:
There is certainly plenty of info on the subject and plenty of knowledge in this forum. The instuctions in the tech pages and the many threads gives you all the info you'll need. I just have these last few nagging questions to answer before I'm satisfied that everything is OK. It just seems anyone with a Viper would hear if the servo zips back and forth when the key is turned on.
Mine always used to and now it doesn't. I'm just trying to establish which is correct. Sorry, it's just the engineer in me.
Click to expand...
yes your's beeing a ER should cycle the servo upon key on,are you gertting
warning lights?/reving it up to 6500 or so you should see the servo open the valves,,do you???????????????

@mikerx,
should do it now,,thats important service steps that should always be
followed on a regulare bases.

@liveride777,
yes droping the idle around 900 should cycle the servo( pull open the valves) adjusting is easy,follow these instructions here
 
Mikerx,
If the sled starts anf runs good, I wouldn't mess with the carbs this year.
The Seafoam should have kept them from gumming up. Now the power valves are a different story. If you've looked the posts much, you realize that they are a real problem area. If they haven't been cleaned in 1600 miles, I think it's time to get your hands dirty. If you look at the posts and check the TY Tech section, you shouldn't have any problems.

Liveride777,
this is a good explaination by Daman on adjusting the valves (along with the TY Tech section).

http://www.totallyamaha.net/forums/showpost.php?p=274355&postcount=4

If you need help, you're in the right place! ;)!
 
im kind of worried about pulling the cable through on the Power Valve when i tighten them. Thats why you say do it gently, correct?
next, is there exact adjustments from the yamaha book?
Hey Bob, where in MA are you from?
 
liveride777 said:
im kind of worried about pulling the cable through on the Power Valve when i tighten them. Thats why you say do it gently, correct?
next, is there exact adjustments from the yamaha book?Hey Bob, where in MA are you from?
Click to expand...
using yamahas method of the 2.5mm gap insures that theirs sufficient slack
left in the cable as not to pull to hard on the cable,that's why yammies way is best way.

you can't pull out the cable on the valve just by tighten the adjuster.
 
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