036 - Does this mean what I think?

[stihltech]

WOW. Too much ado about nothing.
As far as the vacuum/pressure tester, just get the Harbor Freight one. OK for occasional user.
Do you need to do this with your supposed rich condition? YES. I have seen the muffler look way rich with and air leak. It is just the basic test NEEDED for a 2 stroke. I hardly ever use a compression gauge. Internal condition is the MOST important thing.
Clean up the cylinder with fine emery as stated.
Why do all this for a 30 dollar piston? Because the next time could be hundreds of dollars without it.
Your choice.
Good luck.

 

[ZeroJunk]

WOW. Too much ado about nothing.
As far as the vacuum/pressure tester, just get the Harbor Freight one. OK for occasional user.
Do you need to do this with your supposed rich condition? YES. I have seen the muffler look way rich with and air leak. It is just the basic test NEEDED for a 2 stroke. I hardly ever use a compression gauge. Internal condition is the MOST important thing.
Clean up the cylinder with fine emery as stated.
Why do all this for a 30 dollar piston? Because the next time could be hundreds of dollars without it.
Your choice.
Good luck.

I use the OEM Stihl. That thing is about $350 retail !!

More often than not I use it to test a gas line without having to take it out.

 

[lone wolf]

Nope You are wrong. About $200 USD

Depends on who is selling it, he may not be wrong, keep shopping.

 

[Mad Professor]

Here's how I leak testing my Stihl MS038. You could test thru the impulse port and leave the spark plug in. However, I just ground the flare over the spark plug porcelain and pulled it out ... tapped the bore for a fitting. The mini vac what great tool worth every penny in my book. You can always justify mini vac cost to the wife for use in food sealing... My wife has her own...lol

But do You steal the wiffeys to work on equipment?

This 036 Still saw is hurting. Seems like you could rebuild the top end with a P/C kit and be done with it. I have done this several times without failure. Good Luck!

I rescued a way worse 036 I got for free. Even had a 28" ES bar (not sure why). That got moved to my 066/056

A guy had NOS pistons on ebay for $45.

036 rebuild cost

Item	Source	Cost ($)
Seized saw	friend	free
OEM piston /rings	Cheapstillparts	45
Piston pin	Dealer	14
circlips	Dealer	1.40
Gasket set	Dealer	13.75
Clutch upgrade	Dealer	30
Muffler paint	Hardware store	5
Sandpaper detergent	Hardware store	10
Fuel line	Dealer	9.50
Carb kit	Dealer	11
Impulse line	Dealer	4
Upper bearing	Dealer	9
Spark plug		3.25
Oil pump line kit	Dealer	5
20” RSC chain	ebay	15
20” ES bar	ebay	53

 

[Mad Professor]

Depends on who is selling it, he may not be wrong, keep shopping.

Do You have an updated Steal price list?

Good man here (Harley) used to have them.

I paid $180 for an 028S kit many years ago from a dealer, found a 038M kit for $150, my first 038S--->038M conversion.

I don't flip saws and take care of what I have, so not buying many P/C kits. Never a CHI-COM kit.

 

[fields_mj]

JD, Many readers in here may understand how to measure squish, but maybe the OP doesn't.
If I understand the process right, one step of it is to use a length of solder as one rotates the piston to the top.

Another factor of the improved performance process is the impact of judiciously milling out inside the potentially damaged, or a new OEM cylinder. These mods plus opening up the muffler, and altering the squish could definitely improve the performance of the saw, assuming that the electronics, carb etc are all up to snuff. I have never ported any saws but have seen the process and understand the principals. I also know the warnings of knowing where the limits are as far as how far and where one can open the ports.

***** Considering fields_mj's feelings on spending on extra tools and supplies and all his other equipment, home, family needs, I would ask, " is the 036 really the saw I would sink dollars into? Is altering squish, porting etc, worth it, given his tool storage, budgeting his $$$, truck repairs needed, etc? Yes, I know that a gasket delete is a minimal cost alteration, but how much will his saw improve if he just does this partial mod vs. the total package? Where is the cost/benefit threshold of doing porting, gasket delete, muffler mods to this model saw?

Does anyone else agree with me that he should probably start with getting his saw either diagnosed, deem the seals, crank, piston and cylinder to have minimal damage to where he can get the saw running essentially stock by possibly polishing things up and putting new rings in it will render his saw to be within spec. If all works out doing the minimum and if he puts it back together and fires it up, he can have the " acid test" of was that all it needed, and he is good to go? My thoughts are, if he is able to get it running in essentially "stock" form, he at least has his reliable saw back. Once he does, then he is always free to mod it as his time and budget permits?


For reference, the OP lists his saws below.
Suzie Q - Stihl 024 - 18" .325 x .063 mini spline 7 pin rim.
Mini - Stihl 026 - 18" .325 x .063 small spline 8 pin rim.
Taz 1 and Taz 2- Stihl 036 - 18" .325 x .063 standard spline 9 pin rim
Bertha - Stihl 064 - 28" .404 full comp, 42" 3/8" full skip.
The Pretender - G660 - 28" .404 full comp, 42" 3/8" full skip

I used to know how to measure squish, but I'd have to look it up again. If I were going to mod a saw (IMHO) an 036 would be an excellent saw to do since it's relatively light weight and already has good power with little more than a muffler mod. I'd love to do it myself, but I have no experience and don't really want to "learn" on my primary firewood saw. I've thought about porting the 2nd one, but still didn't want to ruin an OEM cylinder and with a simple muffler mod it already puts a smile on my face. Since #1 is already down, if I am going to do any kind of additional mods to it, now is the time. I need to go back and re-do the research on squish and gasket deletes to see what I actually want to do with it in regards to any mods.

 

[fields_mj]

FIWI, I have a vacuum/pressure test kit arriving on Monday. In the mean time, I cleaned the saw up as best I could, and pulled the cyl last night. See the pics below. It looks like its in pretty good shape. Question: What's the best way to clean the carbon build up out of the very top end (by the spark plug)? I'm not sure I can get my hand or fingers far enough up in there to do much with scotchbrite pads.

I think the piston is also in decent shape. The worst of the damage was visible through the exhaust port. Should I be able to get by with simply cleaning everything up and replacing the rings?

Exhaust side



Intake side

 

[fields_mj]

Exhaust side of cylinder




Intake side, pic didn't come out nearly as well.



Now I just need to find the bands I bought 15 years ago to use for getting these pistons back into cylinders. I could have sworn that I saw them within the last year...

 

[SteveSr]

Exhaust side of cylinder


View attachment 1193380

Intake side, pic didn't come out nearly as well.

View attachment 1193381

Now I just need to find the bands I bought 15 years ago to use for getting these pistons back into cylinders. I could have sworn that I saw them within the last year...

Before you put it back together remove the piston and measure the skirt clearance with the cylinder at the bottom (crankcase end) of the bore with a set of feeler gauges. That piston looks like it has a LOT of wear on it.

You can also remove the rings from the piston and insert them into the bottom of the cylinder using the piston to square it up and measure the ring end gap with the same feeler gauges.

Report your numbers here. This may answer a lot of questions.

 

[fields_mj]

Before you put it back together remove the piston and measure the skirt clearance with the cylinder at the bottom (crankcase end) of the bore with a set of feeler gauges. That piston looks like it has a LOT of wear on it.

You can also remove the rings from the piston and insert them into the bottom of the cylinder using the piston to square it up and measure the ring end gap with the same feeler gauges.

Report your numbers here. This may answer a lot of questions.

Can do. What SHOULD the clearance be?

 

[fields_mj]

I know this is going to open a box of worms that I'd rather avoid, but with regards specifically to pistons, what makes an OEM piston better than the a really cheap aftermarket? I'm familiar with investment casting, and understand that a lousy part will have flash and/or pits/voids. I also understand that a good piston is going to have the correct dimensions so that its strong in the right places without having a bunch of extra material that adds to the weight, which is harder on the bearings and such. In these regards, there seems to be a consensus among builders that there are some really crappy AM parts that should be avoided at all costs, but there are a couple that are consistently in the same ballpark as something like a Meteor (sometimes a little better, some times a little worse, but not much difference). Are there other performance and/or durability issues that should be considered?

FWIW, I also realize that Meteor is also an AM brand, but its rare that I hear anyone talking trash about them. I'm sure there's a lemon here and there just like there would be with a Mahle.

 

[fields_mj]

Before you put it back together remove the piston and measure the skirt clearance with the cylinder at the bottom (crankcase end) of the bore with a set of feeler gauges. That piston looks like it has a LOT of wear on it.

You can also remove the rings from the piston and insert them into the bottom of the cylinder using the piston to square it up and measure the ring end gap with the same feeler gauges.

Report your numbers here. This may answer a lot of questions.

0.005"

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

 

[J D]

Looks like the ring grooves might need to be cleaned up better to not bind. Half an old ring works well for this... don't cut yourself.
Make sure there are no high spots or anything that could bur off/ come away

 

[cookies]

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

 

[thompsoncustom]

I know this is going to open a box of worms that I'd rather avoid, but with regards specifically to pistons, what makes an OEM piston better than the a really cheap aftermarket? I'm familiar with investment casting, and understand that a lousy part will have flash and/or pits/voids. I also understand that a good piston is going to have the correct dimensions so that its strong in the right places without having a bunch of extra material that adds to the weight, which is harder on the bearings and such. In these regards, there seems to be a consensus among builders that there are some really crappy AM parts that should be avoided at all costs, but there are a couple that are consistently in the same ballpark as something like a Meteor (sometimes a little better, some times a little worse, but not much difference). Are there other performance and/or durability issues that should be considered?

FWIW, I also realize that Meteor is also an AM brand, but its rare that I hear anyone talking trash about them. I'm sure there's a lemon here and there just like there would be with a Mahle.

I think the biggest thing is just the variation that is found in AM pistons. A super cheap piston could be great or could be crap but with a OEM piston more than likely it will be great tho they can have issues too.

Meteor pistons also have a great reputation of being just as good as OEM and is probably most peoples pick after a OEM piston.

There is a ton of cheap saws out there now some clones and some no name brands and a lot of them run fine so using a cheap piston might be ok your just taking more risk is all.

I've used OEM, Meteor, Farmertec, Dukes, and others without problems other than cleaning up the flashing. All about the amount of risk you want to take vs the money you want to spend I think. I personally have no problem with cheaper pistons as long as they check out ok but I always use caber rings.

 

[cookies]

I think the biggest thing is just the variation that is found in AM pistons. A super cheap piston could be great or could be crap but with a OEM piston more than likely it will be great tho they can have issues too.

Meteor pistons also have a great reputation of being just as good as OEM and is probably most peoples pick after a OEM piston.

There is a ton of cheap saws out there now some clones and some no name brands and a lot of them run fine so using a cheap piston might be ok your just taking more risk is all.

I've used OEM, Meteor, Farmertec, Dukes, and others without problems other than cleaning up the flashing. All about the amount of risk you want to take vs the money you want to spend I think. I personally have no problem with cheaper pistons as long as they check out ok but I always use caber rings.

I've installed about every aftermarket brand of piston in a saw as well and they all have one thing in common, they make noticeably less torque than oem even in a oem cylinder. Some even changed the cutting rpms of the power band, A couple were made of inferior aluminum causing scoring from over expansion, wrist pin gap cast too wide allowing 1/3 of the bearing to hang out, wrist pin to crown height shorter, piston ring orientation pins missing before assembly or falling out during use causing catastrophic damage. The one aftermarket piston I consider using is meteor if oem is crazy hard to get or over the top expensive due to being hard to get! Meteors do need work to get them closer to oem, their windows mostly need opening and reshaping and casting lines require removal. The reason is two fold, weight reduction and air flow...sometimes its off to the point it changes timing...I also put oem rings in the meteor pistons. I typically only put caber rings in cylinders that have some form of plating damage or with goofy over sized ports in a attempt to reduce future damage.

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.

 

[thompsoncustom]

Here's one for ya. China piston on the left Dukes piston on the right. Both are suppose to be 44.7 pistons for the ms260. I didn't end up using either piston but the dukes would have been ok the one on the left is a mile off.

they make noticeably less torque than oem even in a oem cylinder.

I've had it go the otherway as well and make more torque from the piston to crown height being to tall and raising compression you just never know what your gonna get.

 

[fields_mj]

Looks like the ring grooves might need to be cleaned up better to not bind. Half an old ring works well for this... don't cut yourself.
Make sure there are no high spots or anything that could bur off/ come away

Yeah, I hadn't even thought of cleaning the ring grooves yet. Mainly wanted to make sure the cylinder was salvageable before I put any more work into it.


On the OEM vs AM piston, I guess I'm just surprised that there's that much of a difference. I mean its really not that hard to measure the distances from the wrist pin to the ring grooves and the top of piston. Seems like a no brainer that a "clone" would have that right to within 0.005", but what the customer doesn't know doesn't hurt them I guess. I can see where flash, weight, and even the windows would be less than optimal, but dimensionally I would have thought they were closer and more consistent. I'm glad that I asked.

 

[ZeroJunk]

Depends on who is selling it, he may not be wrong, keep shopping.

There are different levels of Stihl dealer cost, although the retail selling price may be standard. The store I piddle at gets the best price level.
When the counter guys run a ticket about the only thing that kicks it back is if it is below store cost. And hell, they can over ride that.

 

[James Sawyer]

Yeah, I hadn't even thought of cleaning the ring grooves yet. Mainly wanted to make sure the cylinder was salvageable before I put any more work into it.


On the OEM vs AM piston, I guess I'm just surprised that there's that much of a difference. I mean its really not that hard to measure the distances from the wrist pin to the ring grooves and the top of piston. Seems like a no brainer that a "clone" would have that right to within 0.005", but what the customer doesn't know doesn't hurt them I guess. I can see where flash, weight, and even the windows would be less than optimal, but dimensionally I would have thought they were closer and more consistent. I'm glad that I asked.

The meteor is darn close to OEM spec from my experience. Casting flash need cleaned up weight is about the same I've found with the Meteor. In my build I decide not to go with the Hyway popup because of the weight. But a guys should check the timing numbers with AM piston swap for peace of mind, I think!

I wasn't able to find much on AM pistons vs OEM, so I did my own investigation. Casting on OEM was not that great in some area as well. Yes, the Meteor window appear different, but on my 461 the lower transfer isn't the cylinder wall so not sure that will make much difference in this case. But I am going clean up the piston and open the window to reduce weight. I just have had time yet.

But to confirm the answer, it not hard to check AM to OEM.