Help with Power valve on a 4FL

[Edd]

Hi Guys;

The PV doesn't move once the bike is started. When switch on it cycles but stays in that position after start upand for the duration of your travels . It doesn't rev past 7000 rpm in second to fith gear only first gear I can rev past 7 000 rpm. I have tested another cdi no change exactly the same. I think it is stuck in closed position haven't verified this yet. How do I set the power valve? When off I lined up the pulley it then cycles and stops in the same position on the mark?

Thanks

Eddie

[tzr-v4]

If it is like on the DTR125 or 200 then the electronics to drive the ypvs motor is in the motor itself not in the CDI box.

Check if the servo-motor has only 3 wires :
 - bullet connector is RPM signal from CDI
 - two way connector is the 12v power supply.

Hope this helps.

[rubberfingers]

My DT125R YPVS is controlled by the CDi (same as a TDR). I think it was just the very early DT's with separate boxes.


Take off the end of the valve and look at the shape, some of them are diamond shaped and can be fitted 180deg out - see photo below



hope this helps

Andy

[Martin77]

Like V4 says above, the 4FL pv is controlled by an internal unit in the servo itself. Either that unit is faulty, or it's not connected to the ignition to sense rpm (so in effect it doesn't know the engine is running). The three wires going in are 12V (brown), earth (black) and rpm sensor (hmm.. black.yellow?) check the black/yellow wire is connected to the black/yellow wire coming out of the cdi.

[Edd]

Hi Guys;

Thanks for the feedback, I did change pv motors around may have fitted a 3xv motor . Will have a look this afternoon. Will keep you posted. I figured out the 180 degree fitment got it wrong initially . Getting there slowly but surely.

Thanks

Edd

[Martin77]

I doubt a 3XV servo would plug into the 4FL loom in the first place... hope you get sorted out though!

[Edd]

Hi Guys;

Changed the motor for a diffrent one and it is working now. I have noticed the pv motor pulley is stamped 4fl. Somebody must have changed the pulley on the initial motor I fitted didn't have 4fl stamped on it. Had to strip both motors as the replacement motor had gear shafts missing on the inside. Finally got one that works now. Problem is it pulls the pv open nicely and then it doesn't stop at full open it continues to turn as rpm picks up and closes the damn thing again.

Are both pv cable inners equal in length? I had one complete cable and one casing and I made the inners same length. I have set it up with y lined up on the hole after cycling, clearly not right

Edd

[Edd]

Hi Guys,

Think I got it now . With pulley aligned on mark after cycling it is actually 1/4 closed and not open as I initially thought. As the revs picks up it closes 1/2 way then starts opening up as revs increases. I get to about 9000 rpm max she doesn't want to rev any higher. Maybe it is set up which I doubt 240 mains, faulty rev counter maybe plausible . I have a boson pipe on it, it should be going to 12k easily from my experience with these pipes. Bike is still brand new changed every single bearing on it may be a bit stiff still .

Somehow I just cant help feeling it is that PV it is not fully open I cant see the pv motor at 9000 rpm . Please put my mind at ease some one.

Thanks

Edd

[Martin77]

Sounds like you need to discount one thing at a time.

Firstly the pv, if you rotate the pv with the ignition off so that it is fully open (use a spanner on the end nut), then disconnect the wires to the servo, it will stay in that position (leave the cables in place). You need to take the pipe off and look up the exhaust port to make sure the valve is indeed fully open and lined up with the port when you do this.

Take it for a test ride, and see if it'll rev out better. It'll be awful below 6-7000, then should kick in really hard and rev right out.

Another way to test where the pv is ay a set rpm is simply to ride it up to that rpm, then turn the ignition off and coast to a halt, then look down at the pv pulley to see where it's sitting.

If it doesn't rev out with the pv held wide open, then it point to something else...

[Edd]

Hi Martin

Another way to test where the pv is ay a set rpm is simply to ride it up to that rpm, then turn the ignition off and coast to a halt, then look down at the pv pulley to see where it's sitting.

Thanks will try this first this week and see where it ends up, never thought of this, thanks again never to old to learn.

Edd

[Toop]

Take off the end of the valve and look at the shape, some of them are diamond shaped and can be fitted 180deg out - see photo below

Andy

In addition on other help, as Andy says, it exist some different pulleys (3 or 4 in memory, 3BP, 2RL,4FU,5AE ...mechanical restraining, mechanical no-reversible without destruction, because evolutive legislation ...)

The only way to get out of the impasse is the path indicated by Martin77, as I already explained here
http://pure2strokespirit.net/forums/index.php?topic=2840.msg31108#msg31108


or here some years ago i write this (in french, sorry I could translate it on the occasion of the lost time)

http://www.yam2stroke.fr/viewtopic.php?f=26&t=7902

pdf version here : http://y2s.free.fr/valve/valve.pdf

*Battery Required (more than 12.6v)
**If the valve rotates in the wrong direction, reverse the cables to the pulley or to the motor if needed
***A cable may be longer than the other, replace the position on the motor and then cross the cables if needed



Hope it help you 

[Mick]

Cables need to run 1-2&2-1...When the PV cycles(just turning key on/off) it should move clockwise (closed)then anticlockwise(open) and remain in that position..

[Edd]

Hi Gents

Thanks for the help. So if I understand correctly I need to switch my cables around if it doesn't cycle in the correct direction? I have cable lined up correctly 1 on 1 and 2 on 2 and it cycle clockwise close position and anticlockwise open.

I will remove exhaust and set it by hand like we do with the zeel ignitions. "Thanks Toop" appreciate. Before I go the root of riding the bike and switching it off to see where pv is sitting.

Edd

[Mick]

I have cable lined up correctly 1 on 1 and 2 on 2 and it cycle clockwise close position and anticlockwise open.

So long as PV pulley cycles as mentioned,and yours does,then no need to alter cables..Always a good idea to pop off exhaust and check if PV is in open position ..

[Toop]

And this is a completely universal way for all valves engines