Power valves... again

sbojan

sbojan

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Nov 18, 2005
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120
Location
McHenry, Il
Just picked up my new 01 SRX. Come to find at least 2 of the 3 power valves have pulled through, on the third valve I was lazy and tried taking the lower allen head bolt out with out pulling the exhaust, stripped the head.

2 questions, what is the best way to get the stripped allen head bolt out and how much can I expect to pay for new power valves?

Thanks
 

New power valves are pricey at about $80-85 a peice, new from the dealer. If you look hard enough you can find some used ones, however, pretty hard to come by. As far as the stripped screw 2 options..try to get at the head, I believe the sides of the screw are splined, with a good pair of pliers or channel locks you might be able to turn it loose OR (what I have done in the past) Cut a slot, with a dremel tool, (make the groove directly in the center of the screw head, from one side to the other, like a flat head screw) in the top of the screw and try using a flat-head screw driver to get it out, I've had success with this method. A little heat never hurts either to break the thread-lok seal. Hope this helps.

--Steve (O.C.)
 
new valves are better than the stock ones as well because Yamaha realized a lot of people were having problems with the cables pulling through and thickened up the material on the top of the valve where the cable attaches. They aren't cheap though as previously mentioned.
 
Thanks for the help, I was affraid they were pricey. I guess if they were only $20 people would replace them instead of cleaning them...

Gotta love people with no mechanical knowledge. My wife just ask why I can't use some of that metal epoxy crap to reattach the valve to the cable.
 
Will probably have it done by the end of the week... pretty simple and straight forward... just fill in the end with weld and then either pull out steel rod or drill a new hole. I'll try to take some pics when I get mine done
 
Thanks Big, I haven't seen a good valve so it is hard to imagine the repair.

Is there a trick to getting the valve re-attached to the cable? I am waiting for new valves but just looking at this it looks difficult to slide the cable in. Do you remove the retaining ring from the spring to let the tension off of the cable so you have some slack when installing or do you remove the cable from the servo so you can pull the slack through?

Thanks for the help.
 
Spring? Are you INSIDE the housing for the power valve cable end that attaches to the cyclinder? If so, you do not need to be. You just need to take the 4 allen head bolts that bolt the power valve housings to the engine, not the 2 allen head bolts that hold the housing together. As far as cable slack, you should be able to gently pull on the barrell end of the metal cable and you should hear your p-valve servo rotate. If it is too tight too pull, then just go to your servo motor (up behind secondary clutch) remove the 3 phillips head srews, pop off the cover (says YPVS on it) and rotate servo(clockwise) until you have enough slack at the other end of cable to install the new valves. The new valves install easily onto the cable ends. You just slide the barrell end of the metal cable into the round hole on the end of the valve. Now would be a good time to adjust all 3 p-valves to make sure they are set properly You can find the adjustment proceedure under -(from main page)--TECHNICAL PAGES/SNOWMOBILE TECH/**ENGINE/YPVS CLEANING AND ADJUSTMENT. I cannot figure out how to post the link, sorry. Maybe someone can help with the direct link. Hope this helps. Am I missing anything else guys?

P.S. Remember to use blue thread-lok on all the bolts after you reassemble.

And also I have done the repair (rebuilding with weld, machining, grinding the damaged end of valve) that BigMax is talking about with success. I keep 3 extra repaired p-valves in the tool box just in case anything happens while away on a trip. AT least you know you have one trashed valve that you can practice on. It is not that difficult and trust me, I am NO master welder or fabricator, by ANY mean. Just like to get my hands dirty.

--Steve (O.C.)
 
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Thanks NY, that makes it more clear. I was afraid to pull on the cable and move the servo but I assume it will reset one I start the sled up.

How excatly do you know when your PV's are not working? I put a few miles on this sled and it had a ton of power, more than my 600 twin, am I in for a big surprise when they are repaired?
 
You can definately feel the difference if you have a valve that isn't opening. I knew it right away when i broke a cable.
 
Oh yeah. If you had a bad or sticking/dirty valve you were loosing ALOT of power. Same thing is your valves are out of adjustment. Whenever I do a p-valve repair or adjustment and ride the sled for the first time.....big smile comes to my face and I say "Ohh yeeeeah. That's the stuff! THAT is what is supposed to feel like!" The actual adjustment for the valves is done up by the servo motor. That end of the cable (by the servo mtr) has two 10mm adjusting nuts (one on the cable and one is a jamb nut). You can see them when you take the servo motor cover off. That is how you adjust the freeplay. So you can pull the cable and manually rotate the servo all you want. Once the sled is running and the servo motor kicks in, it will automaticcaly adjust the cable and valves.

--Steve (O.C.)
 
actually the adjuster nuts are outside the servo, you don't need to pull the cover to see them, just slide the rubber boots back and there they are.
 
Yamaholic22...you are abso-schmutely positively 100% right indeedy correct! How DARE I steer someone in the wrong direction!! <<<SLAP!!>>>

Ummmm, so yeah, like Yamahaholic22 said..uuuhhhh they're like on the outside of the servo case dude....huh huh.....
 
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