036 - Does this mean what I think?

[huskihl]

I believe metallurgy is the biggest difference

 

[fields_mj]

If I'm buying an OEM piston, it comes with rings. Do I use those, or do I buy Caber rings?

 

[fields_mj]

It would be a really good idea for the op to clean all of the crusties out of the muffler before assembly to prevent sucking carbon into the new piston.

That's definitely the plan. To be honest, I was shocked at how much junk was in there. Its one reason I'm not super worried about an air leak (but I'll check anyway). I don't ever remember opening up one of my mufflers and having it look anything like that.

 

[cookies]

Oem rings are superior to caber in sealing and longevity ,it is more important to scuff / ball hone deglaze the cylinder using them for instant ring seating and oil retention although they will eventually seat on their own after several tanks of fuel.
Below is the ball hone I purchased and use on the 034-036-038 cylinders, it works very effectively

Brush Research BC200320AO FLEX-HONE®, 2" (50.8mm) Diameter, 320 Grit, Aluminum Oxide, For Aluminum, Brass, Bronze and Softer Non-Ferrous Materials​

 

[Hman1024]

I have encountered no issues using Stihl oem rings when replacing top end full or partial, IMO.

 

[fields_mj]

Oem rings are superior to caber in sealing and longevity ,it is more important to scuff / ball hone deglaze the cylinder using them for instant ring seating and oil retention although they will eventually seat on their own after several tanks of fuel.
Below is the ball hone I purchased and use on the 034-036-038 cylinders, it works very effectively

Brush Research BC200320AO FLEX-HONE®, 2" (50.8mm) Diameter, 320 Grit, Aluminum Oxide, For Aluminum, Brass, Bronze and Softer Non-Ferrous Materials​

I assumed that was the case on the wrings, but I've never heard anyone say one way or another. The only thing I've ever seen was to always go with Caber rings.

I was under the impression that the scotchbrite pads that were used to clean the carbon build up out of the cylinder was also sufficient for scuffing the cylinder walls in preparation for new rings.

I'm also still not convinced that the existing piston needs replaced. It certainly has a rough spot on it, but nobody has said one way or another whether its toast or not. I don't mind spending $$ to fix everything while I've got it apart, but I'm also not a fan of dropping and extra $50 to replace something for no reason. To my eyes, the cylinder had some carbon build up on it in a couple of the "normal" areas (which easily cleaned up with the scotchbrite), but was otherwise fine. The exception to that was the carbon build up in the top of the cylinder (around the sparkplug). What I could access with the scotchbright cleaned up pretty easy, but I just couldn't get the pad down in there well enough to clean most of it out. I ended up putting a wire brush in the flex shaft for my Dremel to scrub it out and it did a fantastic job. I never could find anywhere on the cylinder where it looked like the piston actually made any contact which has me thinking the piston might be fine so long as I clean out the ring grooves.

I fully plan on replacing the wrist pin bearing, and rings. The wrist pin itself, and the piston are up in the air at this point. Based on cost, and personal experience, I WILL be purchasing several of the circle clips....

 

[cookies]

I assumed that was the case on the wrings, but I've never heard anyone say one way or another. The only thing I've ever seen was to always go with Caber rings.

I was under the impression that the scotchbrite pads that were used to clean the carbon build up out of the cylinder was also sufficient for scuffing the cylinder walls in preparation for new rings.

I'm also still not convinced that the existing piston needs replaced. It certainly has a rough spot on it, but nobody has said one way or another whether its toast or not. I don't mind spending $$ to fix everything while I've got it apart, but I'm also not a fan of dropping and extra $50 to replace something for no reason. I fully plan on replacing the wrist pin bearing, and rings. The wrist pin itself, and the piston are up in the air at this point. Based on cost, and personal experience, I WILL be purchasing several of the circle clips....

Your piston is both toast and worn out. A good piston will have no scarring and still have machine marks...yours is worn to the point of being polished. The machine marks on the piston retain a film of oil reducing piston skirt wear and increases heat transfer out of the piston/rings into the cylinder for air cooling while reducing friction.

 

[fields_mj]

Your piston is both toast and worn out. A good piston will have no scarring and still have machine marks...yours is worn to the point of being polished. The machine marks on the piston retain a film of oil reducing piston skirt wear and increases heat transfer out of the piston/rings into the cylinder for air cooling while reducing friction.

Perfect, that's exactly the answer I was looking for. Thank you!

My local dealership is telling me that the piston (1125-030-2001) comes by itself, but everywhere I look it comes with a new pin, rings, and clips. I'm going to just order the piston from them along with a new bearing and some spare clips. If it turns out the lady at the counter was right, they have new rings in stock so I can just buy them at that time. Their cost for the piston was $100.23. I see one on ebay for $83 plus $8 shipping. Close enough that I don't mind giving the dealership the extra $10.

 

[SteveSr]

0.005"

So, the next question is, does this need replaced or did it clean up enough.

View attachment 1193728

.005" is about twice what it should be. Soon the piston rattle will fatigue the piston skirts and they will break causing much more severe damage.

 

[fields_mj]

OEM piston, wrist pin bearing, and extra circle clips are on order.

 

[James Sawyer]

If that was my saw as others had stated, I'd cleanup the cylinder and see if the grooves on the intake side you can catch a fingernail or feel it. If it's a visual defect probable be ok and I would most definitely buy a new meteor piston ~$40 vs OEM -$90. Its not worth taking chance on OEM cylinder if it can be saved. I don't have a 036 but I do have 034 and 038 great saws... it would be worth it to me.

 

[fields_mj]

If that was my saw as others had stated, I'd cleanup the cylinder and see if the grooves on the intake side you can catch a fingernail or feel it. If it's a visual defect probable be ok and I would most definitely buy a new meteor piston ~$40 vs OEM -$90. Its not worth taking chance on OEM cylinder if it can be saved. I don't have a 036 but I do have 034 and 038 great saws... it would be worth it to me.

Everything cleaned up on the cylinder. Just took a little rubbing with a scotchbrite pad. The vacuum/pressure tester arrived last night. I still need to see if it has an air in the next few days.

 

[James Sawyer]

Have you changed the seals?

 

[fields_mj]

Not yet. New piston arrived today. I figured it would take more than a day to get here. I'm going to do a leak test on it before I go further. I should have done that before ordering the piston, but I got impatient. If the case leaks, I'll have to figure out where I want to go from there. I have a co-worker that tinkers around with old saws, but I don't know if he would do the seals and bearings or not.

 

[James Sawyer]

Well... then how do the bearings feel ok... any up down movement on PTO side. Seals with that old of saw I just plan change them, there not that expensive if you can find them...just not worth the risk if it develops a leak. Unfortunitily, you got pull the flywheel and the PTO apart. The seals aren't hard to change, some can be little stubborn. When you have access to the seals check the seating deep so when the new ones go in, they are inserted to the same depth. To pull the seals get old, slotted screwdriver with appropriate blade width and push it down between the seal inter-lip and the crank. Mark the depth. Remove the screw drive and grind a slot in the side of the blade at appropriate height where when the tool inserted you can be twisted the tool and hook the seal so it can be pulled out. Some people grind another slot up on the shaft and use a socket that slip over outer seal and use the socket as a fulcrum. Something they can be stubborn to lifted out. If the bearings are bad and need replaced this would be the time before go to all the work of putting the cylinder on because you got split the cases. If you feel the bearing are good, installed the cylinder leak test if you want... if you find a leak replace the seal and retest... good to go. Bearings aren't that hard to replace but it takes some skills and tools. There lot knowledge on this site probably... wiser guys then me. I think you got saw that worth putting a few $ in and it'll do everything you want and pass it on to you're kids.

 

[fields_mj]

Well... then how do the bearings feel ok... any up down movement on PTO side. Seals with that old of saw I just plan change them, there not that expensive if you can find them...just not worth the risk if it develops a leak. Unfortunitily, you got pull the flywheel and the PTO apart. The seals aren't hard to change, some can be little stubborn. When you have access to the seals check the seating deep so when the new ones go in, they are inserted to the same depth. To pull the seals get old, slotted screwdriver with appropriate blade width and push it down between the seal inter-lip and the crank. Mark the depth. Remove the screw drive and grind a slot in the side of the blade at appropriate height where when the tool inserted you can be twisted the tool and hook the seal so it can be pulled out. Some people grind another slot up on the shaft and use a socket that slip over outer seal and use the socket as a fulcrum. Something they can be stubborn to lifted out. If the bearings are bad and need replaced this would be the time before go to all the work of putting the cylinder on because you got split the cases. If you feel the bearing are good, installed the cylinder leak test if you want... if you find a leak replace the seal and retest... good to go. Bearings aren't that hard to replace but it takes some skills and tools. There lot knowledge on this site probably... wiser guys then me. I think you got saw that worth putting a few $ in and it'll do everything you want and pass it on to you're kids.

The bearings feel great. No play what so ever. That's the main reason I went ahead and bought the new piston. If it's not leaking, I'm simply not going to tear the saw down that far. I fully understand the risk. I've spent the past 27 years doing these same kinds of things on all kinds of custom and OTS manufacturing equipment. If I didn't have another 036, or my 026, I'd be more prone to replace the bearings and seals so that the entire saw would be rebuilt from the ground up. Fortunately, that's not where I'm at. My other 036 is fully functional, as is my 026. I bought this saw lightly used for $200 15 years ago, and it's been absolutely fantastic. If it doesn't have a leak, I should be able to get several more years of use out of it. If it does have a leak, I'll have to decide what to do. Maybe I'll fix the leak, maybe I'll keep it for parts, maybe I'll sell it with the new hardware to someone who wants to fix it and put that money towards another saw. It's been good to me, but I've also gotten my $$ out of it and have no sentimental attachment to it. It's just a tool that I use to get work done.

 

[Mad Professor]

Get a new oem piston kit, it comes with rings, wrist pin and clips also buy a new oem wrist pin bearing. Make a cylinder gasket out of printer paper and use aviation gasket sealer or copper kote on both sides, this will drop the squish down into the .022-.028 range using oem cylinder and piston. Green or red scotchbrite with oil on it to scuff the cylinder some by hand then wash/scrub it hard 2-3 times with dawn and a sponge to remove the scotchbrite abrasives. Replace the impulse line while it is apart and rinse the bottom end several times with mixed gas and rotate the crank to clean out any carbon/sand/sawdust right before assembly.
I own 3 of these saws, built and sold 3 more and every one I tore down to its underwear and replaced the seals/gaskets, rubber parts...only one has needed a piston, the rest got new oem rings. With my paper gasket trick they all have over 165psi compression after dozens of tanks of gas run through them and 2 out of the three have175psi . New oem piston kit is right at 100 bucks, hyway gasket and seal kit is under 20 bucks, wrist pin bearing is 10.... A OEM elasto start handle is priceless with over 170psi compression!

The first 034 super I got for 100 bucks, I rebuilt the carb and it ran. The saw is almost brand spanking new. I took it out after the carb rebuild and made a couple cuts and it started sputtering and shut off, it restarted and ran after cooling. I fooled with it and fooled with it. Finally I picked up a mity vac tester, I vac and pressure tested every part of that saw. Everything tested perfect except the carb kept bleeding down. I figured out the fuel pump side cover was warped and leaking using the tool, I stole a side cover off a spare carb and it runs flawlessly all day every day!
LMK what size (A/B/AB) those 46mm cylinders are mad...I tucked away a new and a used oem 46mm piston a couple years ago...very hard to find fyi

Not sure A or B? I'll take a picture of the top next time I'm in the garage. The replacement A/B pistons were a compromise made to fit either. Cant' remember which one is bigger? That has been discussed here in the past.

Meteor sizes their pistons too