ms440 Cylinder / Piston Questions

[taddat]

Photo's of cylinders are hard to do but what are your thoughts on this cylinder? I have never pulled a saw cylinder. I want to do it just to learn how. When I do, how do I get the rings back in the cylinder for reassembly? Do I need a special ring compressor?

Thanks in advance for any advice - -


ps.
In one of the photos, there is what looks like a crack in the cylinder near the port - it is just a mysterious photo flaw.

 

[2000ssm6]

You can get a cheap ring compressor from your Stihl dealer or off the net from baileys. The pro saws, like your 440 are much eaiser to take the cylinder off. It has 4 T27 torx bolts holding it on, you will need a slim T27 driver to take 'em out.

Hard to tell about your cylinder's condition, did it run lean? Seize? Or you just want to take it apart.

 

[RiverRat2]

2 K????????

You can get a cheap ring compressor from your Stihl dealer or off the net from baileys. The pro saws, like your 440 are much eaiser to take the cylinder off. It has 4 T27 torx bolts holding it on, you will need a slim T27 driver to take 'em out.

Hard to tell about your cylinder's condition, did it run lean? Seize? Or you just want to take it apart.

hes already got em out!!!!!!!!! LOLOL!!!! if it was running good than put it back to gether and run tha Pizz out of it!!!!




hes trying to get it back together!!!!!!!!:monkey:

Just block up under the piston,,,and line up the rings on the fixing pins and gently put the jug back on,,,, use alittle premix to lube it up,,,

maybe a carb tuning driver to gently push the rings in where needed,,,, it should go right back on especially on the same (Used) rings that came out????? don't force it,,,,, it'll work!!!!!!

 

[Rockfarmer]

On the pistons I have put back in I never used a ring comp. I tried and it didnt work well. I just started the cyl over the piston and the clampedthe first ring tight with my fingers so that it was both ends to the pin and then slid the cyl down over the ring at the same time. Same thing for the second ring and the carefully slide cyl down to gasket/block. Hopefully its just as easy with these tiny saw pistons

 

[super3]

2 K????????




hes already got em out!!!!!!!!!




hes trying to get it gack together!!!!!!!!:monkey:

Looks to me like the piston is still in the cylinder in the 2nd pic. Is the chrome flakeing off on the bottom corner of the port? Doesn't look good.

 

[taddat]

It is a saw I just got off of CL (I hope for a good deal). It runs and starts good. I'm hoping it is a diamond in the rough. I got it for a good price but before I handed over the money, I pulled the muffler and noticed what looks like some scratches. From what I have read on here, the Stihl Cylinders are tough. From the exhaust side the piston looks good (from what I can see).

 

[taddat]

2 K????????




hes already got em out!!!!!!!!!




hes trying to get it back together!!!!!!!!:monkey:

Just block up under the piston,,,and line up the rings on the fixing pins and gently put the piston back on,,,, use alittle premix to lube it up,,,

maybe a carb tuning driver to gently push the rings in where needed,,,, it should go right back on especially on the same (Used) rings that came out????? don't force it,,,,, it'll work!!!!!!

Not yet -but in about 5 more minuets . . . . they will be....

 

[Etced]

ring compressor

A large tyrap works great as a cheap ring compressor.

 

[RiverRat2]

Not yet -but in about 5 more minuets . . . . they will be....

Oh,,,,,,Ok,,,,,,,,,,, I apologize 2K,,,,,,,,,, i guess I need new glasses!!!!!!!! lolol!!!!!!!!


no ring compressor needed,,, as the rock farmer said use the fingers if they fit,,, LOLOL!!!! ican't get my paws in there on most of em!!!!!!

I line up the ringends on the pins,,,, and easem on!!!!!

Good luck,,,,,,,

FWIW,,,,, id a pulled the muffler cover,,,,, had a look,,,,, and if it's running strong,,, put her back in service be fore I wooda pulled the jug!!!!!


If it aint broke,,,,,, don't fix it!!!!!!!!!!

 

[taddat]

Off like a prom dress

Ok .

I can see some minor lines in the cylinder but I can't feel anything at all. Now that the cyl has been unbolted - do I need a new base gasket? Or can I re-use the old one?

Thanks again for all the help !!!

 

[taddat]

The piston has some marks on it (left side of picture) - Replace it????

My guess is the guy who had it before me did no maintenance - - including clean the air filter. The chain was as sharp as a bike chain and the nose of the bar was worn out.

 

[Martinm210]

That looks pretty minor to me. You could probably sand the piston lightly, get some acid to clean off the cylinder and simply replace the rings. Just make sure you get any aluminum transfer completely off, and don't do anything more than cleaning off the transfer with acid and a brillo pad or other simple means.

OEM rings will be less than $50, probably in the $40 range as a guess. Expensive, but worth it.

 

[super3]

OEM rings $21.45

 

[landyboy]

For a ring compressor i cut a strip of 1.6 mil mild steel, wrapped it round the junk piston and bent a flange either end. enough to get a pair of needle nose pliers on it.
Put it round the new piston, squeeze the pliers to push the rings in, slide the piston in the jug,remove the strip. Works a treat and costs nowt.

 

[Bowtie]

The piston has some marks on it (left side of picture) - Replace it????

My guess is the guy who had it before me did no maintenance - - including clean the air filter. The chain was as sharp as a bike chain and the nose of the bar was worn out.

The machine marks are still on most of that piston. I would use muriatic acid and clean up the cylinder as stated above. Re-ring it, or dont. If you can afford to its always a good idea when the thing has unknown hours on it. Slap that baby back together and cut wood!