Power Valve Servo

[sazzansr]

Morning

I have an italian Import NSR, currently rebuilt and streetfightered making 70mph.

The PV is not working, does not do a startup turn, nor does it close @ 2000rpm or open at 65000rpm....... nothing...dead....

I have replaced the servo motor with one off the bay....... still nothing.

Is there any way i can test the motor in case both are knackered?? - before i buy the PV servo 'brain'?

likewise, is there any way to test my servo??

i can't see a servo on ebay at the moment.... any ideas where i might get one??

cheers
s

[Vincent]

There is what's called a potentiometer test for the servo, you'll need a multi meter and a maual for the procedure.

Have you tested it without the cables conected? Sometimes the PV will seize stoping the servo from moving.

[sazzansr]

i have a multimeter and an nsr manual, cant see about the test though.

i tried the new one without the cables fitted to see if it moved on startup/ignition. it didnt.

thank you for your speedy reply.
s

[Vincent]

If it's of any use, (and applicable to the NSR), I can post the test instructions for the Yamaha servo??

I take it the Hondas servo is similar - operated by the CDI and control unit with a single pulley??

[sazzansr]

Sounds the same, thank you

[Vincent]

Just loking at the potentiometer test in the manual and it uses the colour of the wires so I don't think it's much use. You can connect a 12V battery to two wires to test the actual motor, (in Yamaha's case it's Black/Yellow and Black/Red).

The potentiometer test involves wiring up the multimeter in three different ways then turning the pulley by hand and the resulting reading shouldn't be under 7.5 K ohms, (+/- 30% at 20 Deg C).

I did read somewhere that you shouldn't turn the motor by hand too much, not sure how right that is

Sorry this isn't much use, these servos do pack in, I bought a replacement from eBay myself that was clapped out.

[alains]

the controler has 2 connectors (3 wires & 4 wires) and a light green wire on a round terminal
the 3 wires connector has black (+12V after key switch, green ground , red/white from the CDI tells controler engine rpm)
so check with key on if 12V between black & green and if nothing check after the key switch if 12V between black & ground
about this red/white clean the CDI connector because a loose contact can avoid the controler to make the servo-motor moving
the 4 wires connector has white & black/white for power to the DC motor (polarities can be one way or the other but it should move is you feed it briefly with red & green (direct from battery) the other wires (blue/green & white/red) are the potentiometer coupled on the motor axis . the mesure is around 6 KOhms (+- 10%) . the light green is the cursor of the potentiometer , if you mesure blue/green & light green then white/red & light green , the addition must be the same as blue/green & white/red
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the worst day fishing is better than the best day working

[sazzansr]

Thank you for your replies.

DO you know if the OE clocks need to be plugged in?? i have stripped all this and added a non-standard headlight and speedo, would this make any diffence?
Cheers
S

[alains]

Only the tachometer needs to be plugged with the black/yellow and green
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the worst day fishing is better than the best day working

[sazzansr]

Is there any way around this??

I have a Trail Tech Vapour (digital) unit on my NSR and dont want to put the original clocks back on.....

cheers
sara

[alains]

??????????????????
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the worst day fishing is better than the best day working

[G]

You could always hide the NSR clocks about the bike somewhere .

It sounds like the lack of tacho is the issue (makes sense that it would use this), but if I didn't know that, I'd also be testing the powervalve it's self by pulling the cables manually, if you haven't.

[sazzansr]

Sorry to be a divvy, but how does the old tacho work differently to the new digital one built in to the Trail Tech vapour?

does the old analogue clock have a physical trigger/make/break ?

hahahaha where would i hade the clocks on an unfair NSR lol.

i don't want to have to choose between full power or looks

i have manually tested the motor and tried a new one as well as a new PV Control unit. nothing

cheers

[G]

I presume there is some kind of sensor etc there to send back details to the PV unit to tell it when to move the PV; which of course your vapour won't be doing.

[sazzansr]

ITs been a long time now, but I rode the bike without a Power Valve last year and as I'Ve just had it rebuilt though it would be nice to revisit thisissue.

I tested the servo tonight and there is power coming from all wires coming from the servo !! no earth.

This tests the same on both the unit I bought the bike with and the replacement I purchased on the bay.

Do you think i have the wrong one for my bike? Or do I have 2 with the same fault?

We think because of the way the unit gets power and is wiring should mean that the original clocks are not necessary to make the pc work.

And help gratefully received.

Cheers
saz

[alains]

you may PM me with your serial number and i will try to help you
____________________
the worst day fishing is better than the best day working