Powervalve adjustment Tips

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silverstrom
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Powervalve adjustment Tips

#1 Post by silverstrom » Sun Sep 08, 2013 1:40 am

By the book it goes like this. Remove the powervalve pulley cover on the left side. Turn the key on. The valves will cycle and end in the full open position. Adjust the cables until the hole in the pulley aligns perfectly with the hole behind it. That's it....you're done.

Ideally, the best way to do it is to have the pipes off and adjust the cables until you can feel with your finger that the valves are physically aligned with the top of the exhaust ports. This is particularly true with 1UA cylinders where the raised exhaust ports mean the valves will hang lower and into the exhaust ports when rigged IAW the manual. You can rig the valves higher and eliminate most of it, if not all of it. It varies as the valves are not exactly a precision made part and there are variances in size.

Pay attention to the right side valve. If the coupler between the cylinders is worn there will be lag between the left and right valves. Remove the cover from the right side of the right cylinder. if you can rotate the end of the valve that means there is wear and the coupler must be repaired. If the wear is severe you'll be able to hold the right valve with your fingers and when you turn the key on to cycle the valves you'll be able to both see and feel the difference in movement between the left and right valves. There can be no wear in the coupler or the right valve will never fully open.

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Re: Powervalve adjustment Tips

#2 Post by rz250rjapspec » Fri Aug 08, 2014 6:59 am

Also when tightening up the pully, manual states 10nm. Pully location lug will snap off at about 8nm, where you put the 4mm dowel through to hold the pully while tightening. Pully location lug just can't handle the touque, best not to use a torque wrench on this 10mm head, as the tourque wrenches have longer handles and tend to over tighten if not very careful. Just nip it up gently.
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JonW
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Re: Powervalve adjustment Tips

#3 Post by JonW » Fri Aug 08, 2014 9:30 am

Bear in mind that it isnt the same startup with the Zeel, it cycles differently and leaves them closed until the bike starts. Otherwise all good.
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Re: Powervalve adjustment Tips

#4 Post by seahorse » Wed Sep 24, 2014 9:49 am

Re the tightening, of the cable adjusters. If you keep in mind there is a tiny cogs in the servo motor pulling the cables 1 and 2, then finger tight adjustment then a light nip of the lock nut is all that is required on those adjusters, All that is occurring is the cables are rotating the valves that should be putting up very little resistance.
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Re: Powervalve adjustment Tips

#5 Post by hondaror » Wed Sep 24, 2014 12:29 pm

This is where we add how important jetting is in the PV function. A well jetted, as near to full burn as possible combustion is best for these puppies, as spooge gums things up and ruins the function with carbon and oil build up. Running too rich with the idea that safe is better attitude only causes problems here.
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Re: Powervalve adjustment Tips

#6 Post by JonW » Wed Sep 24, 2014 7:35 pm

+1. gummed up PVs kill cables as well... not as cheap to replace as you would think either...
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
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Re: Powervalve adjustment Tips

#7 Post by Consciousness » Sun Aug 23, 2015 3:02 am

Thanks for this. I've got issues unknown at the moment other than the PV's are not sealing dispite a new coupler and thrust washers, will have to take the cylinders off to see whats going on in there, one thing i do know is that my neutral light does not come on until after the bike has started, the PV's don't cycle nor do they open at 6k as they used to. I've recently added a fan and a Daytona temp gauge and think i or friend may have messed up the wiring somewhere.

Mechanics are one thing but electrics are truly alien to me.
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Re: Powervalve adjustment Tips

#8 Post by JonW » Sun Aug 23, 2015 9:01 am

sounds like the right track David, good luck mate!
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82 RD350LC decapitation project
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Re: Powervalve adjustment Tips

#9 Post by Consciousness » Sun Aug 23, 2015 1:43 pm

JonW wrote:sounds like the right track David, good luck mate!
Cheers Jon, right now its a W.I.P. instead of a Whip lol.
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Re: Powervalve adjustment Tips

#10 Post by magee » Tue Dec 01, 2015 1:29 am

I have watched two YouTube videos of the power valve pulley rotating when the bike is reved but the videos show the pulley turning in opposite directions ? Which is the correct rotation also can the valves be installed 180 degrees out
I have looked at the valves from inside the bore and it does not look right
Does anybody have any pictures of the valves in the open and closed position looking from inside the bore
Sorry for the dumb questions but I am new to these power valves

Thanks in advance
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Re: Powervalve adjustment Tips

#11 Post by silverstrom » Tue Dec 01, 2015 2:28 am

Open is easy. Look in the exhaust port and you'll see it's full open when it is flush with the top of the port.

When you turn the key to the ON position the valves will turn full aft (closed) and then go back and stop at full open. When you start the bike they go to full closed. As RPM climbs the valves will start to open at 5550 and reach full open at 9450 for 31K cylinders. 6000 and 10200 for 1UA cylinders.

People have connected the cables backwards and run the valves backwards. If you do that, the valves will close as RPM increases, with an obvious loss of performance. It shouldn't be difficult to connect them properly, but people still get it wrong. The servo is numbered 1 and 2 and the connection points at the pulley housing are numbered 1 and 2. It's hard to get wrong if you can count to 2.

YouTube is full of bad videos giving bad advice. Garbage in, garbage out.

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Re: Powervalve adjustment Tips

#12 Post by magee » Tue Dec 01, 2015 9:31 am

silverstrom wrote:Open is easy. Look in the exhaust port and you'll see it's full open when it is flush with the top of the port.

When you turn the key to the ON position the valves will turn full aft (closed) and then go back and stop at full open. When you start the bike they go to full closed. As RPM climbs the valves will start to open at 5550 and reach full open at 9450 for 31K cylinders. 6000 and 10200 for 1UA cylinders.

People have connected the cables backwards and run the valves backwards. If you do that, the valves will close as RPM increases, with an obvious loss of performance. It shouldn't be difficult to connect them properly, but people still get it wrong. The servo is numbered 1 and 2 and the connection points at the pulley housing are numbered 1 and 2. It's hard to get wrong if you can count to 2.

YouTube is full of bad videos giving bad advice. Garbage in, garbage out.
thanks for the information, it looks to me like the valves have been installed wrong, it does not matter if the valves are open or closed the port is never fully open the valves always covers the same area and is never flush with the top of the port.
Will have to take them out and have a proper look.
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Re: Powervalve adjustment Tips

#13 Post by silverstrom » Tue Dec 01, 2015 3:40 pm

It is just about impossible to install the valves wrong. It is likely poorly rigged. Back the adjusters off and rig it properly. If there is too much tension on one cable the valves won't rotate properly. Are your servo and controller working properly?

Also, check the coupler between the cylinders.

Post pics here so we can see what's happening.

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Re: Powervalve adjustment Tips

#14 Post by JonW » Tue Dec 01, 2015 10:41 pm

A point of note....

When you follow the manual and put a dowel (drill bit works well) thru the pulley into the case to line up the parts, DO NOT SWITCH THE KEY!

Someone recently told me they had accidentally done this and it caused a bit of carnage, so beware....
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
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86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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Re: Powervalve adjustment Tips

#15 Post by magee » Wed Dec 02, 2015 12:37 am

Update on my problem. Seems the person who had the bike before me installed the power valves 180 degrees out
Reset the correct way now good to go
Thanks for the information
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