reusing wristpin circlips / ring-gap alignment??

So my manual says never to reuse a piston wristpin's circlip, does anyone know why? I have 4 used ones and I guess I'm just hoping I can avoid tracking down a couple of these.
Also, when reinstalling pistons is there any reason to stagger the endgaps of the rings. I know the rings will move around when firing, but it sort of makes sense to me to stagger. Any wisdom for me?
Thanks

Metal fatigue on the clips would be my guess and yes, the rings need to be spaced 120 degree from each other to minimize compression loss.

HenryKrinkle wrote:

So my manual says never to reuse a piston wristpin's circlip, does anyone know why?

The endless cold-hot-cold cycle will detemper the steel.

Also, when reinstalling pistons is there any reason to stagger the endgaps of the rings. I know the rings will move around when firing,

Idon't think the rings do move. When I lifted the cylinder off mine, the rings were right where they were supposed to be: gaps on #1 and #3 facing straight forward, gap on #2 straight to the rear.

I assume it is to help with compression but also to make the cylinder wall wear more round.

the circlips will usally distort when they are removed so i don't even take chances i always throw them straight into the garbage the second they come out of the engine so i won't get confused or tempted to reuse them

HenryKrinkle wrote:

So my manual says never to reuse a piston wristpin's circlip, does anyone know why? I have 4 used ones and I guess I'm just hoping I can avoid tracking down a couple of these.
Also, when reinstalling pistons is there any reason to stagger the endgaps of the rings. I know the rings will move around when firing, but it sort of makes sense to me to stagger. Any wisdom for me?
Thanks

as far as i know the rings dont move..staggering the gaps keeps blowby to a min......for what it s worth my new pistons (mtc) came with teflon buttons
instead of circlips...i had never seen or used them before, but they seem like a vastly better way to
keep pins in check....just my .02...keith

buttons work great if you are taking the motor apart from time to time like us dragracers but i probably would not use them for a street bike as they do wear and allow the piston pin to move around it the pin boss and small end causing a bit of extra wear to the pin ,pin bosses and small end

timebomb33 wrote:

buttons work great if you are taking the motor apart from time to time like us dragracers but i probably would not use them for a street bike as they do wear and allow the piston pin to move around it the pin boss and small end causing a bit of extra wear to the pin ,pin bosses and small end

hey tim,
just out of curiousity, anything i can do to minimize that wear....anal on the oil changes?..

Thanks guys.
Any reason to stagger at 120 rather than 180*? Also, I'm only having to replace one piston w/ new circlip - but should I just do all 4 while I'm in there. Can't find them at Z1 - where can I find new ones?

I'd ask at several websites for them:

1. www.aperaceparts.com
2. www.fastbygast.com
3. www.scnitzracing.com
4. www.redlinecycle.com
5. www.flowbenchtech.com
6. www.dynoman.net
7. www.sudco.com
8. www.americanclassix.com
9. www.kzzone.com

If these websites do not have them maybe they know who does.

Don't reuse the circlips. when you pry them out you twist them just a bit and then when the piston reciprocates the clips actually have enough inertia to collapse just a little bit and since they are now twisted they will work their way out and into the cylinder wall. thats also why when you're installing them you should put them in with the open end either straight up or straight down. I just ordered mine out of a Bell industries catalog. CW15 from wiseco. Thats for a 650 though. They were about a buck a piece.

HenryKrinkle wrote:

Thanks guys.
Any reason to stagger at 120 rather than 180*? Also, I'm only having to replace one piston w/ new circlip - but should I just do all 4 while I'm in there. Can't find them at Z1 - where can I find new ones?

My FSM says to do the 180 stagger on the three rings, but I am not sure it would make a whole lot of difference if you did the 120 stagger.

Thanks for all the help fellas. I'm starting to get real excited about this build (my first time) and I really appreciate you all sharing your knowledge and experience. I couldn't do it without you.
Time to call around and find some new circlips for the 650. And get my pistons/rings sorted out.