125-200cc 125 PV question

Just putting new top end in. Does the PV open fully(valves almost disappear looking up exhaust) or do they stay down a little? Been a while but thought they opened fully(recessed right into cylinder)? Maybe I did the mechanism bolt up too tight? I'll post a photo in a bit.

If it is the large, older style of power valve, they don't completely recess out of the way when fully open. The very back side will still protrude into the exhaust port at the rear. It will only be a couple of mm. Probably designed this way to increase exhaust velocity through the end of the port and into the pipe.

Nah newer smaller design Walt(got another top end cheapish). What have I done?

they the right way around
walts the man - Im not sure that they fully recess out of the way but you may want to try adjusting power valve bolt location in slot on side
Good job getting a newer cylinder

The newer ones should recess flush with the exhaust port. Definitely check your power valve adjustment bolt. Also check to make sure the little slotted arm that actually pulls the power valves open has its set screw fully tightened in the hole in the shaft. Make sure the linkage is correctly slotted on both shafts.

Ok weird that gotta adjust it isn't it? They can only go one way round as far as I can tell! I hope I don't have to take cylinder off as hot everything tightened down ready to go!

Yeah it was the one on ebay the other week bloke in Sydney. 2013 wr125 so same bike. Told me it'd done 800km & was as new. When I got it it's got 3-4 scratches in nikasil(ring & piston minor marks too) that are deep enough to catch ya nail. I'd say a bit of dirt inhested. Not particularly happy but buyer beware I guess. I'm just gonna run it & see how it goes. Head was like new

Sorted. I tightened grub screw up in PV housing/shaft(front of cylinder) with valves partially retracted. Loosened, pushed valves to fully closed & tightened & all is well again. Valves sit right down into cylinder at rest & retract fully(exhaust port unhindered) when PV is actuated. Weird as I've never done that before. Teach me to rush the job & drink beer whilst doing it. Cheers all

PS good on the husky engineers for making it so ya can get that PV access cover off(just though!) front of cylinder without removing it & also being able to tighten grub screw in situ.

you got to stop drinking beers when doing stuff haha - Yeh great bikes to work on
Good on Walt for knowing the issue .
I have a newer 125 cylinder and power valves but its damaged from a circlip possibly from my lack of skill when I put it on my 08 - keeping it for a 139 project one day

bagga mate i'd rethink this as a scratched piston can fail a scratched bore can flake and that goes right to the crank. IMHO send her out and get her plated/sleeved and pop a new pill in the bore to be safe. just saying bud. glad ya got yer PV sorted. mreeep mreeeeeeeeeep!