Help on a motorized power valve.

[weasel]

Ive just got a TZR 125 2RK model, and the power-valve has been pissed about with badly, so iam looking to get a motorized kit for it. Does anyone know where i can get a second from, and also, how hard are they to fit?

And also if there are any TZR owners out there, what sort of top end do you get once de-restricted, since iam not actually old enough to ride it yet!
____________________
Its still restricted officer.... Honest!

[simon1221]

The motorised Pv kits are almost extinct my friend. I couldnt seem to find anyone who made them when mine broke.

You could try breakers etc and a few pop up on ebay every few months - prepare to pay hundred(s) of pounds for it though.

De-restricted would give you about 90mph on the clock, but realistically that would be about 80-85mph in real life.

How badly is it nackered? If you fully derestrict it without the motor, you will have sod-all power at low revs (<5k).

Hope this helps.

Simon
____________________
DNA50 (sorry) ->> TZR125l >> GPZ500S

[weasel]

The one that is on it, isnt actually a motorized one, its just a standard YPVS, but the previous owner lost the cap that holds the valve in place (shut), so i just spins around merrily.
Is there some sort of happy medium where you can have the valve half open, so youve got a bit more poke lower down the revs, and maybe comprimise a bit on top end?
____________________
Its still restricted officer.... Honest!

[weasel]

The one that is on it, isnt actually a motorized one, its just a standard YPVS, but the previous owner lost the cap that holds the valve in place (shut), so i just spins around merrily.
Is there some sort of happy medium where you can have the valve half open, so youve got a bit more poke lower down the revs, and maybe comprimise a bit on top end?
____________________
Its still restricted officer.... Honest!

[simon1221]

Yes.

Getting parts for the standard one shouldnt be too hard.

You can pin it in place somehow, the halfway position you are talking about is actually when it is restricted.

Lets hope somebody else posts who has pinned there Powervalve in the open or half open position.

You could alternatively try posting here or in this forum's workshop section on info on doing it.

I would get it sorted out before riding, as it will be difficult to drive and will be unpredictable, one moment you have power, another you wont.
____________________
DNA50 (sorry) ->> TZR125l >> GPZ500S

[Bomberman]

[simon1221]

Any chance of telling him how to do it then?
____________________
DNA50 (sorry) ->> TZR125l >> GPZ500S

[Bomberman]

I confess that I didn't actually do mine myself, it came like that officer
However, looking at my Haynes and google result this makes sense. Although the second post has confused me a bit Is it the 2RK like mine, the last of the rear drum models and standard UK spec?
____________________
'Allo! My name is Inigo Montoya, you killed my father, prepare to die!
'89 TZR 125 - '94 GPZ500s - ZK3 GSXR600 Alstare

[Liono]

I've got a few links which may be of use when trying to have a fiddle with the Powervalve. They apply more to a TDR or DT, but I think that they have the same engine as a TZR anyway.

https://www.geocities.com/yamaha_dtr125/tuningf.htm

https://www.bikechatforums.com/viewtopic.php?p=270112

https://www.dirtridersinternational.com/topic.asp?TOPIC_ID=612&whichpage=1

https://www.yamaha-rd.com/forum/

Searching through the forums on the last two links might be worth a go as well, as lots of similar topics seem to get posted there.

[weasel]

Nope, its the 2RK with the Disc rear brake.
Is there anyone out there who has made a home-made valve opening kit, I.E a lever bolted to it, whuch you just pull back to open it, at the desired revs/speed, and shut when you slow down, if not, do you think this type of device might be possible?
____________________
Its still restricted officer.... Honest!

[Bomberman]

Errr, I'm not being rude mate, but after about 20 seconds of riding the bike you'll understand why that won't work. Or at least why it would be a total pain in the arse
Basically you're going to have to hunt down the part that you're missing I'm afraid. At least until (if) you get lucky and find a full YPVS system. Last one I saw (Ebay) was 6 months back> It went for a bit too IIRC
____________________
'Allo! My name is Inigo Montoya, you killed my father, prepare to die!
'89 TZR 125 - '94 GPZ500s - ZK3 GSXR600 Alstare

[weasel]

Cheers for your help mate, i guess it would be awkward, and it would also make for good conversation...
Officer: And why were you hanging down looking at the left hand side of your bike fiddling with something at 50m.p.h sir??
Me: Err.. Umm.. Err.. I had an itch...
Cheers for all your help, i may just have to bite the bullet and buy a brand spanking new one for 200 quid from Tinklers.
____________________
Its still restricted officer.... Honest!

[Bomberman]

lol, I didn't think of the rather obvious derestriction that would imply You could claim you were adjusting the fuel tap... until they found a lever in the side of the engine block I also didn't know you could get them new. Interesting
____________________
'Allo! My name is Inigo Montoya, you killed my father, prepare to die!
'89 TZR 125 - '94 GPZ500s - ZK3 GSXR600 Alstare