advice needed on pinning power valve



  • this is on an 1989 engine its not the orginal head
    I have the power valve (diamond shaped type)
    the right hand soiid cap
    I have the left cap that has a hole in the middle that you put a bolt through into the pv



  • when you put the bolt through the cap there is a little hole in the cap that I think should have pin it in but its missing

    I bought another cap I was told would work this doesn't have a pin either it has a tube shaped part with a slot in that sits in the cap

    ![alt text](image url)0_1481748633089_14122016309.jpg
    this is what I have does it simply need a pin to lock it

    0_1481748696533_14122016310.jpg
    here is the head

    0_1481748725698_14122016312.jpg
    what is this part for



  • @dan28 Welcome to the forum man,

    Not sure what the problem is... I have little experience with Non-Servo DTR, but I had a pinned power-valve way back when following this assembly.

    https://www.yamahamotorcyclespares.co.uk/spares/epcImages/9118/1.jpg



  • I looked on the forum it says you use a drill bit in the hole in the cap to hold it in position I thought if no servo was fitted it would have a pin as standard
    Does Anyone have a photo of the parts needed for the left hand side



  • Read it, don't understand the problem.

    Surely you can just assemble the powervalve and then lock it in place if you so wish to.

    If you have the servo and wires then leave them attached in the open position then job done



  • @Calum said in advice needed on pinning power valve:

    Read it, don't understand the problem.

    Surely you can just assemble the powervalve and then lock it in place if you so wish to.

    If you have the servo and wires then leave them attached in the open position then job done

    The problem is I sold the original head that already had the Pv pinned this head came with out a Pv an I didn't take any notice of how it went together

    If I put the bolt through the cap an into the Pv shouldn't there be a pin in the cap (shown in photo)that fits into the indent on the side of the barrel stopping the cap from being able to turn

    Or am I over thinking it an just need to do the bolt up tight if so then why does the cap an barrel have those indents for a pin to fit in



  • I've never actually looked at the setup of a non pulley version.

    What's on the inner side of part 20 in the diagram. Looks like it's already fitted to the end of the end cap. Does it have a diamond shape that holds onto the end of the valve itself?

    From the parts diagram it doesn't look like there is a separate pin so I would guess not. If it came apart then im sure Yamaha would have listed with it's own part number. So unless your end cap or part 20 is broken then it should all be fine. Try fit it all together and then put your finger up the barrel and try and move the valve.