power valve operation

[jools]

I've never had trouble with power valves before now so have sort of taken them for granted 

apart from the cycling of the valve and servo on power up, which leaves the valve open - at what point do the valves close?

Is it as soon as the engine is running ?

[Paul]

Jools
They will start to open about 6000 and be fully open at about 9000.
They allow more low down power and gradually give you full power as exhaust port effectively raises to fully open.

[jools]

Cheers Paul,

I understand what they do. I think there is a problem with the 2ma in that after the power up cycle they are not closing at all.
From what you are saying they should close as soon as the motor fires up and stay closed until around the 6000rpm mark.

With the 2ma there is a separate PV controller to the CDI, so as the powervalves cycle ok on power up i would assume that the CDI is not passing a "close" signal to the PV controller....

jools

[tzr-v4]

On the 2MA, when ignition is on the valve cycle and will stay fully opened.
This is for easy starting... (never been difficult to start ;-) )

Then when engine is started the valve will close.
Normal opening is from 6000rpm to 9000rpm (around these figures).

[jools]

Thanks for the answers,

I'll have to do a bit more investigation.

With it being a F3 CDI I'll be a bit disappointed if its cactus - I do have a 2KM unit I can replace it with though.

[Paul]

Jools
When you said "taken them for granted" I took that to mean you werent sure exactly what's they're purpose. No disrespect intended mate.
Most the ypvs keep the PV open after cycle, I say most as I can't remember, I run zeel/IGNITECH on all my bikes. If you start it and look again they'll be closed. Like Olivier says. If I recall again, some bikes the PV won't activate in first gear to prevent wheelies. That might be a myth unless its controlled internally in cdi.

[jools]

none taken Paul 

I had another check tonight and thought I would go through the wiring again before condemning anything.

The F3 ignition components and PV controller are very simple and do away with the wiring loom.
It was at this point that I noticed that there is no wiring diagram in the F3 manual.
The nearest I had for comparison was in the TZ250S/T manual.
I noticed that the only part that could be open to question was the connection between CDI and PV controller, which also acts as the kill switch connection which on this bike was permanently earthed.
It made me wonder if this might be the problem so I disconnected the kill switch connection and checked. The powervalve closed after starting and started to open when revs increased 
I also had the tacho attached to this connection too. Then I found a spare orange wire to the ignition that was hidden under the spiral band - maybe this should be the tacho connection. Neither the F3 or TZ manual show this connection although standard Yamaha practice is to use this (or the grey wire)for the tacho.
This is a total loss set up with a lithium battery for the PV controller and the tacho and temp gauge.
It was getting dark so I called it for tonight. Still not too sure.

[tzr-v4]

On TZR250, RZ500 the orange wire coming out the CDI unit is connected to :
- the coil
- the tacho
- the YPVS black box

Same signal and it is a -200v pulse with a frequency double as the RPM as the ignition is a waisted spark one.

From memory :
Servo motor is a 4 + 1 connector.
4 ways connector is motor connection (2 wires) + 5volts supply for potentiometer
Bullet connector is signal from potentiometer middle point

Here my 2 strokes projects web http://ypvsbox.free.fr/?lang=en_us
YPVS servo connection at the end of old page http://ypvsbox.free.fr/old/box_en.html

[Yatsushiro]

It was at this point that I noticed that there is no wiring diagram in the F3 manual.

Page #23 of the F111 Kit Manual has a wiring diagram ?

[jools]

It was at this point that I noticed that there is no wiring diagram in the F3 manual.

Page #23 of the F111 Kit Manual has a wiring diagram ?

Thanks for that Yats - it seems its missing from my hard copy.......... I'll double check the wiring again.
The bike had an aftermarket kill sw which was connected to earth permanently so its odd that it even ran at all.....

Thanks also TZR-V4 for the signal description - its good to know what is supposed to be happening.

Jools

[mboddy]

Hi Jools. Note that some of the aftermarket 'kill' switches are actually on/off switches. It could be a battery on/off via the black ground wire.

[jools]

I had another hour or so today investigating.
It was wired as per the diagram so I'm still a bit confused.
Having junked the kill switch altogether I checked the operation of the power valve again.
Nothing - it refused to close again. Which is odd because it worked fine last night !
I checked it with another servo I had with the same result.
The only other PV controller I had was from the TZ250S but the connector to the servo was a  6 way item which included the white/red wire which is an external bullet connection to the normal 4 way connectors, so I had to replace that too. just plugging them into the circuit had the power valves operating as they should so it was just a case of replacing them.
Not sure if its possible to repair the power valve controllers - I did notice the TZ one is unpotted.

[mboddy]

Two stroke race lab in greece will repair PV controllers and also fit them with dip switches so you can program them.

[jools]

Cheers Mark,

I'll look into that.

Just back from dyno session, we cut it short as my settings were not far off the mark.

The red trace was the firsat run on 250 mains, drilled airbox - no filter
We then tried removing the airbox. The bike would not take WOT for the test ! I couldn't believe it would make that much difference. Raising the needle made little difference so back on with the airbox and down to 240 mains which gave the green trace.
We are going to experiment with some 32mm carbs after the first round, but for now as the cooler days approach will go back to 250 mains.

Note:
The 59W (TZ250S) powervalve controller started opening around 8000 rpm and was fully open at 9000 on the tacho, which was reading 500rpm high.
I'm wondering what the stock 2MA operates at......
I also need to compare static ignition settings:
The F3 CDI states 0.84mm BTDC, while the TZ250S gives a value of 1.3mm
There is no ignition graph in the F3 manual (that I can see)
This is the TZ ignition map for reference. The static figure for the F3 would indicate that it may run more advance maybe ?

[tzr-v4]

Here the data on YPVS from BDK engineering :

With DIP modification to adjust the range... as 2 stroke lab in Greece does.