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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> rear shock - accessing the restrictor needle
Post Info TOPIC: rear shock - accessing the restrictor needle
jasparach


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rear shock - accessing the restrictor needle
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On the subject of rebuilding the rear shock, has anyone ever removed the restrictor needle that is in the shock shaft? Does anyone know which end of the shaft it would or should come out

if indeed it does come out at all. There is supposed to be an o-ring living in there from what i can gather but that is all i know it. I would dearly love to know whether this is the case or not.

John.



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1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.
TTRfan


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Hi John

Did you see that in my guide here ?

I tried to find a way to access the restrictor needle but failed and ended up cutting up a shock shaft to satisfy my curiosity.  You would need to remove the restrictor needle's seat to also remove the needle but I can't see that it would be possible to remove the seat without destroying it.

Brian

20190216_155239.jpg



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jasparach


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Hi Brian,

I did see your guide and thats what i am using to carry out the work as it is the best guide i have found to follow. You wont find the information that you just displayed in the that photo anywhere else only here. Brilliant. I too am on the verge of cutting a shaft just to see what is holding in there. Do you see the part of the shaft Brian where the needle sits in the shaft? Is that part of the bore in the shaft wider than the section above and below it? Is that right from what i can gather?

John

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1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.
TTRfan


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For the sake of completeness here are all the photos I took John!

The diameter of the bore below the needle is smaller as it only has to accommodate the long 3.5mm diameter aluminium rod. Once you get to the 6mm diameter needle the diameter of the bore is the same from there to the top. The tapered end of the needle sits in the steel bush.

The shock needs to have good pressure for the rebound clicker to work!  https://ttr250.activeboard.com/t54461644/shock-rebound-damping-adjustment-doesnt-click/

Can I ask what has prompted you to consider chopping up your shock shaft?  

Brian



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jasparach


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I have a good shaft with good chrome but i cant get any good out out the needle so i am trying to get it out but i'll be damned if it will move. I didn't know from which end it was fitted into the shaft so was considering a sacrifice to get to the bottom of it and know for future reference and to know how it works. That is my only reason. Did you ever remove one without damage or was that the one and only time?

John.

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1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.
TTRfan


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The needle with O ring will have been inserted in the rod at the top (wide) end first with pointy end upwards. Then the bush will have been driven down on top. 

To get the needle out the top, you first have to remove the bush which is the big challenge.  Maybe try getting an easy out to grip on it and pull? 

If your shaft is good then it's worth saving as to get a damaged one re-chromed is nearly £100.

Why do you want to get the needle out of yours though?  I don't understand "any good out out the needle" cry



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jasparach


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The needle is stuck solid in shaft and wont move under any circumstance. Won't budge and i have tried hitting it down from the bottom to drive it out the top but no joy.

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1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.
TTRfan


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You won't be able to drive it out the top if the bush is still installed John.

If it is stuck in the up position can you try pressurising it to move it back down?  Need to apply about 150psi to make it budge though if the needle is stuck to the bush.

 



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jasparach


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I had the shaft rechromed and since then there is not a hope in hell of moving it. Whatever took place in the process has fubared it so removal is the only option. I'll drill the seat out and see then if the needle will come out of it

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1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.
jasparach


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Well i have liberated a needle and seat from a damaged shaft and will fit it to the good shaft that i drilled out the seat from and the needle tapped out from below. Mind you I don't really know how you could get it out under normal conditions when the seat would have to be reused.

Where the needle seat sits in the top of the shaft is slightly smaller than the access hole in the top so that it can tap in tight again. 

 



-- Edited by jasparach on Sunday 8th of March 2020 01:37:22 PM

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TTRfan


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Well done!

Do you know exactly how far down the shaft you will have to drive the seat?

Why do you think your needle was jammed?



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jasparach


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As far as i can see Brian there are 3 different sizes to the internal size of the bore, 1. is for the aluminium rod to insert from below, 2. is for the needle and the needle seat to sit in to achieve a tight fit and 3. is the top of the shaft to allow the needle and seat to drop in and down to where they locate. I wonder could one of those induction heaters be used on the top of the shaft to heat it up sufficiently to allow the needle and the needle to be driven up from below and thus avoid damage to them. What do you think on that?

John

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1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.
TTRfan


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Sounds plausible John but what are the chances of anyone ever having to do that?  biggrin

My solution would be to try and find an "easyout" that is just the right size to grab on the seat to pull it out. 

If heat was used then you would need to have a correctly sized O ring to fit on the needle as the original would be bound to get damaged.



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jasparach


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That's true and i sincerely hope that i wont ever have to do it again.

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1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.
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