Can anyone help in sorting a power valve problem? My understanding is, when the ignition is switch on, the servo operates to open the power valves and then closes again. When started, as the rev's increase, the servo begins to open the valves. My MC18 R2 has a mind of it's own. At ignition on, the servo does not move. At 2000 rpm the servo moves to roughly the middle position. A few hundred rev's more and the servo returns to the closed position. This obviously results in erratic power delivery. I have, for the time being, disconnected the wires to the servo and manually turned the servo to the open position.The TPS seems OK when checked with an ohm meter. I cannot think the controller or the servo are at fault because they both do something. Any suggestions would be most appreciated.
Thanks
Alan
PS
Where can I buy non standard main jets? I currently make my own, but, I can only get drills in 0.05mm increments, apart for a few letter sizes.

This seems to be normal operation to me.
The MC21 does the same thing. It's a way of checking the full open position markers of the valves.
It's so you don't have to rev the bike to 12000 at a standstill to find the max open position of the servo.
With the tank off, run the bike and hold it at around 2500rpm. The servo should move to the full open position. Then mark that point with a pencil. Once this is done, turn the engine off.
Now you can set the valves to the high position using the pencil mark to turn the servo to the right place.
You set the valves by sticking your finger up the exhaust port. Once this is done you can check the pointer position on the backplate on the barrel. Again, make a new mark if it's slightly out.

So, I'd reconnect the servo and ride the bike as normal if it was me.
You may need to adjust the idle speed lower. If this is set a bit high it can cause a kind of hunting situation as the valves cycle.

Thanks for the prompt reply.
I have read the workshop on how to set the power valve. Maybe my description was a little long and possibly confusing. I was trying to get across that the servo does exactly opposite to yours and the workshop description. In that, at switch on, nothing happens. At 2000 rpm the servo operates and just above 2000 rpm the servo closes and remains closed no matter how much the rev's rise. I hope this clarifies the situation.
Thanks
Alan

alanhrc wrote:At ignition on, the servo does not move.

It doesn't unless the powervalves aren't closed.

alanhrc wrote: At 2000 rpm the servo moves to roughly the middle position. A few hundred rev's more and the servo returns to the closed position.

This is normal behaviour.

alanhrc wrote:Where can I buy non standard main jets? I currently make my own, but, I can only get drills in 0.05mm increments, apart for a few letter sizes.

Here, part number is 99-101-393-SIZE

alanhrc wrote: just above 2000 rpm the servo closes and remains closed no matter how much the rev's rise.

How high have you reved it while watching the power valve motor?
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Turn the servo to the high position with the ignition off. See if it moves when the ignition's switched back on.

As John says, does the servo start to move again when you hit around 8000 to 9000rpm when blipping the throttle in neutral?

I have bought an MC21, and have the same question about the power-valves.
Should the servo motor turn while I switch the ignition on? Like it does on my RD350 YPVS or not? Cause I started to suspect that the servo motor is burned ( or somehting else) how can I check if the power valve system ( servo motor, ECU etc) work fine?
When I turn on the ignition nothing happens, checked the wires etc...looks like servo motor doesnt have its own fuse like on the RD3500.
Thanks!

rz350 wrote:I have bought an MC21, and have the same question about the power-valves.
Should the servo motor turn while I switch the ignition on? Like it does on my RD350 YPVS or not?

No, PGM unit will not perform the "test cycle" of Yamaha bikes.
You will have to blip the throttle and check that the rc valves are moving.
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Does it matter if the bike is started or not?
If anyone can give me tips on adjustment would really appriciate.

Yes it does,
you should start and rev the bike to see the rc valve pulleys moving.

On the servo there are marks for "HI" & "LOW" positions and you can find adequate info using the search engine in this forum as well.
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Are you sure that the bike has to be started to see if the power-valves work?
Cause I read this here about setting them:
With the kill switch set to the run position, turn the ignition on with the key/card. Allow the Valve to cycle to the start setting.

Doesnt say that the bike has to be started, and it doesnt make sence to me either- I believe it should be like on RDs operate after the ignition key is turned.

CAN somebody please tell me if the power-valves turn and set with the ignition turned on, or the bike needs to be started? (MC 21)
Thanks in advance

rz350 wrote:CAN somebody please tell me if the power-valves turn and set with the ignition turned on, or the bike needs to be started? (MC 21)
Thanks in advance[/i]

I'll tell you that same as I told alanhrc, if the RC valves are already closed (i.e. in the start position) they don't move whern you turn the ignition on.

If you feel like it you can reach though the fairing and rotate the bottom one by hand to the open position (with the ignition off), it'll then move to closed when you turn the ignition on.

This is definatly true for the r5k/r6k mc18, all mc21's, mc28's, the PGM-II NF5 RS and the PGM-II F3 NSR. I presume it's also true for the MC16, r2j/r4j mc18 and pre PGM F3/RS's.
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Will check it out this coming week....Thanks

Looks like my ECU part that is responsible for the servo-motor is burned, someone had secured the servo-motor in HIGH position with a screw...
Since I dont think I will be getting new ECU, guys whats the best position to secure the power valves?
High?
Low?
In the middle?
Thanks for your replies!

The position you fix your valves to depends on your riding style.

have it closed if you do a lot of start stops, won't get full rev range.

Have it mid way if you want some compromise.

Have it fully open if you ride it 100% all the time

Or you can be inventive and make a hand actuator

Auto store... cheap shift light... a little creative wiring?

OK, it's not perfect, in fact it'd be about as crude as an LC, but it's hardly rocket science either!
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