Circlip ideas and thoughts

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I sorta remember one brand of saw didn’t use wrist pin retainers. [emoji848]

Lombard or maybe Roper used a Westinghouse micarta button. [emoji108]

But it was a reed valve saw and possibly wouldn’t work in piston ported situation. Transfers being where they are.
 
Things to look for...
Clips that when slightly twisted, stay twisted. Junk.

Clips that use the giant bent tang to actually hold the wrist pin in place because the groove in the piston is so incredibly the wrong size that the wrist pin will slide out across the clip if the ridiculous tang is cut off. Replacing clip with OEM is not a fix as most times the OEM is smaller wire and makes the situation worse as the unsupported tang will fail regardless of who made it.. Pretty much a useless piston unless you are a gambler that likes destruction in which case, go nuts.

Clips that out of the box are different sizes and shapes using the eyeball gauge. Double check with calipers because eyeball gauge gets worse with age.

Be suspicious of a piston box that has many extra clips, especially if those clips eyeball gauge out at different sizes and shapes.

Ends of wrist pins might not be chamfered because the flat end of the wrist pin is needed to help make up the slop from the extra dodgey fit, plus it gives more surface to ride on the tang and what not. Double check stuff before sneaking a chamfered wrist pin.

Having said all that, never had a clip fail. I do have a drawer of new clips and a drawer of used clips. Same with wrist pins and bearings. I do cut off the ridiculous tangs if I am using those clips. I do grind in a relief to allow removal if it is needed. I have more confidence in re- installing a used OEM clip than most new AM clips, or pistons, cylinders. Still though, I have not had any AM clip failures so far.
 
Ever notice the OEM clips bend easy and lose their shape and OEM is better spring steel?

I don't know about the latter, but I do know that the smaller Stihl clips are not very forgiving beyond a certain point when sliding them into place with a notched tweaker and I've had several simply collapse rather than 'give' enough to slip into the pin boss groove. Bought a bag of extras just for that reason. 'Course Stihl would have you use their installation tool which applies uniform force around the clip circumference and all but eliminates that problem. Don't know too many guys that can afford em, tho. I sure as hell can't. And there's a separate tool for each pin diameter.

Speaking of installation tools, has anyone had experience with any of the other insertion tools out there?

And one last armchair quarterback suggestion, (from me anyhow), if you don't already do it; Install the circlip that would be the least accessible if the piston was in place on the saw first, and do it before installing the piston. Much easier for that first one regardless of your method. If you can't get that one right, you probably shouldn't try the other one.
 
I don't know about the latter, but I do know that the smaller Stihl clips are not very forgiving beyond a certain point when sliding them into place with a notched tweaker and I've had several simply collapse rather than 'give' enough to slip into the pin boss groove. Bought a bag of extras just for that reason. 'Course Stihl would have you use their installation tool which applies uniform force around the clip circumference and all but eliminates that problem. Don't know too many guys that can afford em, tho. I sure as hell can't. And there's a separate tool for each pin diameter.

Speaking of installation tools, has anyone had experience with any of the other insertion tools out there?

And one last armchair quarterback suggestion, (from me anyhow), if you don't already do it; Install the circlip that would be the least accessible if the piston was in place on the saw first, and do it before installing the piston. Much easier for that first one regardless of your method. If you can't get that one right, you probably shouldn't try the other one.
Best installation tool if you have old eyes is a pair of reading glasses.
 
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Hard to see here but, there are notches filed in the jaws that give a good grip on .030”-.040” wire.
 
Surprised no one has mentioned indexing the clip openings up or down as opposed to sideways...

Messing with the annealing, hardening and temper on steel that is of unknown metallurgy doesn't seem like a good idea in this application,
could and likely does require very specific temps and cooling times (quenching in oil, water or even air for instance), chemical seasoning, etc.
Even if you knew, it would require a high temp oven as open flame is just too uncontrollable on something this small and thin.
Very easy to make them have plenty of spring but still be too brittle or otherwise weak in a host of ways.
Especially dealing with chinesium-who-knows-what-it-is steel and how much each clip may vary from the next.
 
I sorta remember one brand of saw didn’t use wrist pin retainers.

But it was a reed valve saw and possibly wouldn’t work in piston ported situation. Transfers being where they are.

The Poulan 3400-4000 series do not use them, as the wrist pin is a press fit into the small end of the con rod & it uses two WP bearings pressed into the piston. No reeds used on those saws either.
 
In my limited experience, I think it mostly has to do with metallurgy and paying attention to what one is doing.

I only use oem or meteor clips. Meteor pistons and clips certainly have different gauge and groove than oem do. The pins are almost always a different length as well.

Once one starts mixing and matching parts, no matter the quality, one better be on his game.

I frequently cut down 1128 pins on the lathe. Only the ends are tapered, and the oem pin is too long to fit into the meteor 044 or 046 slug. You’d be surprised how the thickness grows with a few thou off the ends.

08E48665-D46F-4DB1-9D62-D35DD6DD4A2C.jpeg F1F47A98-D806-48E4-A5CF-F11CB23457B6.jpeg E45044E5-894E-42AC-AC95-7EAAF98396D4.jpeg 742D945A-1AAD-4463-8B66-81780D180744.jpeg 6294B27C-E88E-4559-B670-56BE48F4BA9C.jpeg
 
Surprised no one has mentioned indexing the clip openings up or down as opposed to sideways...

Exactly! The clip is a spring. The big tang "ears" add mass to the spring. At high RPM the mass and the spring can compress enough to pop the clip out of the groove.

The way to prevent this is to remove the ears if at all possible and install the clip with the gap facing either up or down. Definitely NOT left or right... even with OEM clips. I think Stihl may even specify this in their repair manuals.

BTW, the ears should NOT be what is holding the pin in the slug. If it is you have got the wrong size clip!
 
If you have installed a questionable set of clips or a dodgey piston...

After installing the piston push the wrist pin against each clip and look for clip movement, clip might pop out, or you can see that it is using the tang to hold it in place. Sometimes the pin will slide through the clip.

While pushing the pin against the clip try to rotate the clip using the friction from the pin, if the clip rotates easily with little pressure chances are it will not stay put.

If the clip has one tang, drag the clip around by the tang, usually pretty easy in the direction of the tang but trying to use the tang to push the clip toward the bare side the clip will dig in a bit. Cheapy clip may not have enough tension to dig in. If no tang, both sides should bite. Even with the bite you will still be able to move the clips just take a bit of effort compared to a clip without enough tension.

Sometimes there is not much that can be done, sometimes a different clip should be used. I use a small needle nose pliers or a modified flat screwdriver to move the pin around. OEM or AM I check the install of clips, take less than a minute as long as they are good and have caught more than a few future problems. There were and probably are a lot of AM clips out there that simply do not have enough spring to hold shape/tension after installation.

Long handle micro flat screw driver is my go to clip installer/remover if no tang, small dia, short nose needle plier if it has a tang.
 
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