064, 066 MS650, MS660 info thread

[ManiacalMark]

I didn’t have any problem ordering a 650 piston

 

[popopboat]

I didn’t have any problem ordering a 650 piston

Yeah but, where are you located?

 

[Maintenance Chief]

Already asked something similar but,
it appears like 064 piston has fairly narrow skirt, has it ever caused a problem ? with wear and stability?

The factory 064 has proven reliable track record, worrying about oem parts quality is not necessarily.

 

[popopboat]

The factory 064 has proven reliable track record, worrying about oem parts quality is not necessarily.

Works for me Chief!
Just needed a small encouragement, thanks

 

[PogoInTheWoods]

Run 40:1 high quality synthetic mix for added assurance.

 

[popopboat]

Run 40:1 high quality synthetic mix for added assurance.

Yep, i run atleast 40:1 on all of my equipment (if it doesnt require richer)

 

[ManiacalMark]

Yeah but, where are you located?

Pennsylvania, where are you?

 

[PogoInTheWoods]

​

 

[Maintenance Chief]

View attachment 294416​

Haha ,great visual!

 

[popopboat]

Alright, here's the pistoney! And it has the 650s "ears"
Looks like OEM Stihl by Kolbenschmidt, BUT, according to my humble experience there are few oddities. (thats just a scratch, no cracks involved)


There are nearly NO machining marks, only few on the upper part.


No marks on rings whatsoever.
Thick wristpin.


And finnaly, WHATARDOOOS?

 

[PogoInTheWoods]

I'd say you got your $40 worth by the wrist pin alone! Snip the ears off the clips if you're of the camp that they'll break off and destroy your top end if you don't. They may actually be OEM for that piston as Stihl did use double ear clips with some assemblies back in the day. If in doubt about using the clips, get a couple OEM for comparison. They're $.99 ea. if you can find them locally. I'd still ensure a proper fit before committing to even newer non-eared clips. The spring steel quality can vary quite a bit as can the retaining slot size.

Folks who are adamant about using OEM circlips in aftermarket pistons aren't necessarily getting a better fit or extended reliability..., especially in cheap pistons with poor manufacturing tolerances. I usually run what comes with the kit unless there are glaring issues. Using what fits usually works.

 

[popopboat]

Yep, i cut clip ears too.
I mean, usually i dont have too much trouble pressing clips together with fingers only, but these are the hardest clips ive encountered, rock solid.
But the strangest thing is the lack of machining marks
i mean they are here, but skirts are extremely smooth.

 

[PogoInTheWoods]

You may want to measure the skirt clearance just out of curiosity.

 

[popopboat]

You may want to measure the skirt clearance just out of curiosity.

Roughly measured on the bottom is around 51.996 mm, but ill check it tomorrow with micrometer(screw gauge).
Can anyone post dimensions (micrometers), cant find them.

 

[PogoInTheWoods]

I'm talking about the piston to cylinder clearance at the bottom of the skirt as you would measure (roughly) with feeler gauges or with a bore gauge and micrometer for more precision. .002 to .004 would probably be on the good side of what would be considered tolerable for a 52mm piston, but don't quote me on that.

 

[Definitive Dave]

Alright, here's the pistoney! And it has the 650s "ears"
Looks like OEM Stihl by Kolbenschmidt, BUT, according to my humble experience there are few oddities. (thats just a scratch, no cracks involved)
View attachment 294840 View attachment 294841

There are nearly NO machining marks, only few on the upper part.
View attachment 294838

No marks on rings whatsoever.
Thick wristpin.
View attachment 294842

And finnaly, WHATARDOOOS?
View attachment 294839

this looks like a counterfeit, everything about it is wrong, wrong pin, wrong clips chunky construction, bad windows, $ marking instead of the K over S makers mark, also should not be stamped STIHL and KS instead, wrong series id number on top. This company sold very believable fakes to dealers as " just as good as OEM", years back and they still pop up occasionally. Also $40 is waaaay less than dealer cost for an OEM 064 piston kit
just my .02 adjusted for inflation
Dave

 

[PogoInTheWoods]

I'd say he was still damned lucky to even find it in Croatia, let alone for 40 bux.

 

[popopboat]

Alright side by side comparison with an old OEM one.


It says Stihl and KS on both, its not a dollar sign.


Same numbers


Im damn confused, what would you fellas do? Refund or change for a meteor or?
I was a bit suprised with the price but they sell OEM meteors and AIP pistons for half the price compared to others so i thought... maybe...?

Is it possible to contact stihl or kolbenschmidt about this?

EDIT: should i post in other thread or this one is okay for this stuff?

 

[jacob j.]

I'm with Dave - that looks counterfeit.

 

[Lightning Performance]

I agree with both of them about that piston.

What you don't see is the voids internally or poor casting techniques. The material used will always be in question.
You might be better off with a new Hyway piston... seriously.

Modern materials is what makes or breaks any well made piston. Tune it fat if your going to run it. Buy new clips. Wire has come a long way and heat treatments. I tend to leave old stuff in the past for modern hipo engines. If was great then it might still be good today but marginal stuff makes a nice ashtray or folk art.
My 2ct