Working on an 064..

[lwhaples]

Did some trading this weekend and have a 064 to play with The owner was never really impressed with the saw.Recoil needed fixing,so after that I was ready hear my new saw.First tug told me it wasn't what I thought it should be. I got 100 psi with my tester,so I pulled the jug. The piston looked clean,thinking it was swapped out. Gasket .036 which I thought was way thick.Then solder was .037 and was never touched by the pistonand that's without the gasket. Guess I need to look at the piston closer,after market maybe. Compression was 130 without the gasket. Still baffled some. Dang CAD!

 

[huskihl]

Did some trading this weekend and have a 064 to play with The owner was never really impressed with the saw.Recoil needed fixing,so after that I was ready hear my new saw.First tug told me it wasn't what I thought it should be. I got 100 psi with my tester,so I pulled the jug.View attachment 42342 View attachment 42343 The piston looked clean,thinking it was swapped out. Gasket .036 which I thought was way thick.Then solder was .037 and was never touched by the pistonand that's without the gasket. Guess I need to look at the piston closer,after market maybe. Compression was 130 without the gasket. Still baffled some. Dang CAD!

Shove a ring up the bore , square it up with the piston, and measure the ring end gap. Might just need new rings, and a tighter squish

 

[lwhaples]

I did add a set of rings when I put back together.Least it has a nice KS jug.

 

[huskihl]

I did add a set of rings when I put back together.Least it has a nice KS jug.

How much compression now? Where's your squish at?

 

[lwhaples]

Compression went up to 130. I need to recheck squish.

 

[huskihl]

Should be about 160 or 170ish at .025

 

[Brewz]

My brother bought an 044 and it was a turd

120 psi with a new piston and squish measured at .060

It turned out the cheap aftermarket piston had a .022 lower crown height.

Installed a meteor, set squish at .020 and compression came up to 175 psi and it now runs like it should

You may have a similar issue.

 

[Deets066]

The piston looked clean,thinking it was swapped out. Gasket .036 which I thought was way thick!

I've never seen a stihl gasket that was .036, somebody has been in that saw for sure

 

[Brewz]

Meteor on the right.

Skirt length was the same but crown height was shorter on the unknown brand AM piston when both mounted on a wrist pin.
This not only killed compression but messed with the port timing as well.

if you still don't have under .037 squish with no gasket, something is wrong.

Either the cylinder has had its squish machined too high or the piston is machined too low.

If I were you I would get a new Meteor piston which will come with Cabers and do what I have done with the pistons to check them.
If they are right, I would be sending the





Here is the measurement from the base to the squish of a stock KS 064 cylinder



Here is the measurement from the top of the wrist pin hole to the piston top of a meteor 064 piston. Equates to bang on 17mm
Piston height top to bottom was 1.7"

 

[Brewz]

I've never seen a stihl gasket that was .036, somebody has been in that saw for sure

agreed!

Usually about .020

 

[lwhaples]

Thanks for the info Brewz. Something to look for when I go back in.

 

[bigbadbob]

I got a 064 meteor and it was short also,, next one was ok. Not sure what was up with that. Maybe thats it!! LOL
BBB

 

[jmssaws]

It might have a 046 piston in it.
Also the oem paper gaskets were 035 or so.

Regardless your piston isn't correct.
Crown height is off for some reason

I do use a meteor some in a 85cc cylinder because you can get 70% on the exhaust and never have had one that was short,046 piston will be what you describe and make a stinker out of a glorious pedigreed masterpiece of a saw.

 

[jmssaws]

Metal gasket should be around 017 and with a stock chamber and a squish around 020 it should be close or above 170lb.

 

[junkman]

I was thinking it is a 460 piston also ,that will lower the compresion a lot because it is too short .

 

[jmssaws]

I build a absolute mountain of 064's and never have got a short meteor and it's the only one I use since a oem is 130$

I read a tech bulletin on when they switched to the thin metal gasket they use now which tightened squish but the piston and cylinder remain the same.
There's slight differences in width between the ks and mahle oem piston but the crown is the same.

 

[Adirondackstihl]

 

[jmssaws]

 

[Chainsaw Jim]

Are any of them coming out with a taller head than spec?

 

[lwhaples]

Piston on the left is OEM 064. The one on the right has no markings. Woops! Reverse what I wrote.