Stihl 044 questions, new piston required.

[freeasaburt]

Hello,

I bought an old, sorry looking 044 a couple of months ago, finally found the time to take a look at it. Cylinder, exhaust, some other parts are original. Carb says 'Hong Kong' on top of it, so it's an aftermarket one I guess
Piston is scored but not terribly, I'm hoping that the cylinder still has enough plating left and that I can remove transfer (would be the first time I do something like that, found good advice online though). It's the older model by the way, with the 10mm wrist pin. Didn't take the cylinder off yet, need to buy a new, long torx wrench first.

I called my local Stihl dealer, asking about availability of oem piston and carb.
Piston: €220...
Carb: no longer available.

So I'm looking into aftermarket parts, I'm not gonna spend that amount of money on a piston, whether I like it or not.

Does anyone have recommendations? Hyway, for example?

Also, carb wise, just in case it's one of the bad Chinese ones: any recommendations?

Thanks in advance!

 

[grizz55chev]

Hello,

I bought an old, sorry looking 044 a couple of months ago, finally found the time to take a look at it. Cylinder, exhaust, some other parts are original. Carb says 'Hong Kong' on top of it, so it's an aftermarket one I guess
Piston is scored but not terribly, I'm hoping that the cylinder still has enough plating left and that I can remove transfer (would be the first time I do something like that, found good advice online though). It's the older model by the way, with the 10mm wrist pin. Didn't take the cylinder off yet, need to buy a new, long torx wrench first.

I called my local Stihl dealer, asking about availability of oem piston and carb.
Piston: €220...
Carb: no longer available.

So I'm looking into aftermarket parts, I'm not gonna spend that amount of money on a piston, whether I like it or not.

Does anyone have recommendations? Hyway, for example?

Also, carb wise, just in case it's one of the bad Chinese ones: any recommendations?

Thanks in advance!

Go with a Meteor piston , good as original in most cases, comes with Caber rings, also OEM quality. Be sure to specify the 10 mm wrist pin. You have the makings of a desirable saw, post some pics if you can!

 

[freeasaburt]

Will do, need to clean it up first though .
The idea is to get it running properly now, check all I can first before I do 'cosmetic' upgrades (e.g. the starter rope cover is damaged).

Thanks for the advice, I'm going to check Meteor availabilty around here. Unbranded (I guess Farmertec) €20 pistons are easy to find but I'd prefer something with a bit better reputation.

Attached video shows the piston's condition.

 

[farmer steve]

Some of my old 036's had the Hong Kong carb on them. I m pretty sure that was original. Just checked my buddy's 044 sitting here with oem carb and it says HK. Walbro

 

[freeasaburt]

Interesting! Thanks for the feedback!

I found a Meteor piston for €56 shipping included, on a German webshop. Think I'll be ordering that one tonight.

 

[lone wolf]

Will do, need to clean it up first though .
The idea is to get it running properly now, check all I can first before I do 'cosmetic' upgrades (e.g. the starter rope cover is damaged).

Thanks for the advice, I'm going to check Meteor availabilty around here. Unbranded (I guess Farmertec) €20 pistons are easy to find but I'd prefer something with a bit better reputation.

Attached video shows the piston's condition.

Well take the cyl off and see what the total damage is and try to clean it up before you buy anything.

 

[freeasaburt]

Good advice, thx. Going to the hardware store after work for a long T27. The one I have is crap, not worth the risk of using anymore.

 

[chilipeppermaniac]

Good Luck, freeasaburt.

I began to learn about how saws work when my original 1994, 026 fought me to start and run well. I discovered the main issues were fuel line and carb related. The crap fuel and occasional use caused the fuel lines and impulse line to gum up. Once I got the lines and filter all replaced, it still would not run. So it was either rebuild my old carb or get a new one. As luck would have it, I found an OEM carb to buy for under $30. I bought a 2nd 026 that was a known good runner, too. I put the new carb on the original saw and it fired up nicely. If it didn't, I would have at least had another known good carb from the 2nd saw.

In researching how saws work, how to diagnose and ensure that a saw is sound and healthy, I learned several vital lessons.
As we all should know, Internal Combustion engines need good operation of all the systems that combine Fuel, Air, Fire, and Compression.

So, As you know, a scored cylinder/piston will affect the compression, but it will also have an effect on the air component due to loss of vacuum needed to draw fuel/air from the fuel tank to carb to be burned and exhausted. I still remember a friend's uncle who rebuilt 2 of my string trimmer carbs one night. After the 2nd one, he and I tried starting the trimmer. His trained ear heard something I would not have caught. He said it sounded like the exhaust was plugged. It turned out that mud daubers had blocked the opening with mud.

The other aspect of the air scenario is the saw needs to have good seals. Here is where vacuum and pressure checking is key. A saw with air leaks can cause a lean running scenario that can cause damage to top ends too. The key tests are meant to verify that the carb is healthy, the crankcase is healthy, ( crank seals) good. Also, believe it or not, the fuel tank/filler cap venting needs to be tested too.

The other fuel related concern is proper and good quality fuel/oil mix. Many a good saw has been ruined when a saw owner or someone he lets use the saw, puts straight gas in it.

Good luck on the 044. I took a chance and bought my first 044 sight unseen from a well reputed seller on this site. I still think it was a bit crazy, but despite the seller being from Europe, I took the chance. It is a great saw. 044's rule.

 

[pioneerguy600]

Go with a Meteor piston , good as original in most cases, comes with Caber rings, also OEM quality. Be sure to specify the 10 mm wrist pin. You have the makings of a desirable saw, post some pics if you can!

Good as original, bit debatable as they are heavier and make less compression but they are well made, machined well and made of good materials, however the ones made for the 10 mm pin are in reality 12 mm blanks just bored for 100mm pin but the 10 mm connecting rod is much narrower than the 12 mm con rod where the pin fits in and because Meteor used a 12 mm slug there is a huge space between the shoulders /bosses where the connecting rod sits allowing for rod walk sideways.

 

[freeasaburt]

I read about that too, also saw a picture on a webshop exactly showing what you described, in the description it said that they had no problems with it whatsoever though. I guess I'll have to find out. Maybe add spacers? Also, would grinding on the piston (if done correctly, of course) be a good idea, to bring the weight down, and possibly improve flow? (I still have to check it how the ports line up, of course, but if someone has some useful advice here, I'd be glad to hear it).

 

[ZeroJunk]

Run a 5 MM .8 tap in your muffler screw holes before you go too far. That right one looks a little funny.

 

[pioneerguy600]

I read about that too, also saw a picture on a webshop exactly showing what you described, in the description it said that they had no problems with it whatsoever though. I guess I'll have to find out. Maybe add spacers? Also, would grinding on the piston (if done correctly, of course) be a good idea, to bring the weight down, and possibly improve flow? (I still have to check it how the ports line up, of course, but if someone has some useful advice here, I'd be glad to hear it).

I grind on them myself but I can`t recommend it to anyone not experienced at where it is safe to remove metal. I am running Meteor pistons without any problems so far, just put that in the post so others would not be surprised if they bought one.

 

[grizz55chev]

Good as original, bit debatable as they are heavier and make less compression but they are well made, machined well and made of good materials, however the ones made for the 10 mm pin are in reality 12 mm blanks just bored for 100mm pin but the 10 mm connecting rod is much narrower than the 12 mm con rod where the pin fits in and because Meteor used a 12 mm slug there is a huge space between the shoulders /bosses where the connecting rod sits allowing for rod walk sideways.

As a hobbyist, I appreciate your input. That being said, cost vs OEM makes the Meteor piston a reasonable choice. If the saw is intended for sale or repaired for a pro, full disclosure as to the parts used is a must. Lone Wolf made the suggestion to pull the saw apart before ordering a piston, excellent advice. It's also a good idea to do a pressure-vac test before teardown and try to find and identify any problems that may have caused the saw to score the cylinder and address this to prevent it happening again. Stay away from any aftermarket rubber parts, particularly the carb boot and fuel, impulse lines, as well as the crank seals. Good luck!

 

[chilipeppermaniac]

Lone Wolf made the suggestion to pull the saw apart before ordering a piston, excellent advice. It's also a good idea to do a pressure-vac test before teardown and try to find and identify any problems that may have caused the saw to score the cylinder and address this to prevent it happening again. Stay away from any aftermarket rubber parts, particularly the carb boot and fuel, impulse lines, as well as the crank seals. Good luck!

Yup grizz55chev. I was just revisiting my facebook and one group I am in is a stihl chainsaw fans group. Just happened that the IPL and Service procedures were posted a couple days ago for Series 1111 saws. The service procedures in them can be adopted to run the vac and pressure tests for an 044, 026 etc saw. I will post links to see if they work and can be of use for the OP etc, copy and paste these in your address bar.


file:///C:/Users/ADMIN/Downloads/Stihl%20050%20Workshop.pdf

file:///C:/Users/ADMIN/Downloads/Stihl%201111%20Workshop.pdf

 

[chilipeppermaniac]

Another thing to account for if and when anyone rebuilds their saws is to check for play in the crank. If I can find it, as it has been quite a while, I will post how to check this.

 

[pioneerguy600]

As a hobbyist, I appreciate your input. That being said, cost vs OEM makes the Meteor piston a reasonable choice. If the saw is intended for sale or repaired for a pro, full disclosure as to the parts used is a must. Lone Wolf made the suggestion to pull the saw apart before ordering a piston, excellent advice. It's also a good idea to do a pressure-vac test before teardown and try to find and identify any problems that may have caused the saw to score the cylinder and address this to prevent it happening again. Stay away from any aftermarket rubber parts, particularly the carb boot and fuel, impulse lines, as well as the crank seals. Good luck!

In one of my 044`s I am running a Meteor piston that I did a good bit of grinding on it and it has a good many hours on it now with no problems to date, my brother runs it for firewood duty, 12 cords at a time, truck loads of long tree length hardwood delivered to his yard. I was told by rather well versed gentlemen that the wide space the 10 mm rod would set in would allow the rod to tip or walk sideways and that would cause needle bearing breakage at both the piston pin and the big end bottom rod bearing due to uneven loading. I went ahead and used the piston and as already said it has not broken anything yet. The Meteor I used had a lower crown distance from the pin to crown so the squish was larger but a shave of the cylinder base brought it back down to reasonable clearance of .022

 

[chilipeppermaniac]

I am also sure there are many more experienced tech guys here who can also add their own procedures to saw building.
The more I think of how-to procedures, step by step as a build goes together, I always look for things to do to maximize reliability and performance.

Having rebuilt my top end of my old 1998 KX 250 Dirtbike, I think about how to transfer the methods of dirtbike assembly to power saw builds.
My goal for dirtbike building is good compression, easy starts, and of course speed. But for me, it all begins with the easy starts. Nothing worse than taking a spill on the bike and losing places while trying to restart the bike.

Same goes for saws. If the saw constantly fights the owner to start, it costs a pro his money, and if a homeowner, firewood cutter has troubles, they typically have to pay to get their saws serviced. Sometimes they pay and pay and pay, depending on how good their dealers and saw shops are at real diagnosis, coupled with their own limited knowledge of how saws work or fail. Limits on how to diagnose and really know a properly running saw vs the causes of poor performance. These are the things I seek out to learn.

I know I have posted good clips of a total start to finish diagnosis according to a factory diagnosis and testing order of procedures in some threads in the past. But since it has been a few years since I could visit regularly, I will have to hunt for them. For all who are interested, I think these were some of the finest demo's out there.

 

[chilipeppermaniac]

In one of my 044`s I am running a Meteor piston that I did a good bit of grinding on it and it has a good many hours on it now with no problems to date, my brother runs it for firewood duty, 12 cords at a time, truck loads of long tree length hardwood delivered to his yard. I was told by rather well versed gentlemen that the wide space the 10 mm rod would set in would allow the rod to tip or walk sideways and that would cause needle bearing breakage at both the piston pin and the big end bottom rod bearing due to uneven loading. I went ahead and used the piston and as already said it has not broken anything yet. The Meteor I used had a lower crown distance from the pin to crown so the squish was larger but a shave of the cylinder base brought it back down to reasonable clearance of .

pioneer, I have a curious scenario with 2 pistons for my 075 that I've had broken down for about 3-4 years now. I bought it 2nd hand and well worn.

Some piston scoring and yet the bore didn't look terrible. However, I purchased a NOS OEM, Stihl Piston and Cylinder to use for the rebuild.
The curiosity is how the 2 pistons have different shapes to the cutouts for the transfer ports. I intend to weigh these 2 pistons to compare the original which I think may be grams lighter due to wear, less metal in places, and to get a reading on how each does if I use both in the saw and compare.

 

[rocketnorton]

put a meteor in a 10mm 044
made plastic [uhmw or teflon - cant remember which] spacer rings for small end

 

[pioneerguy600]

pioneer, I have a curious scenario with 2 pistons for my 075 that I've had broken down for about 3-4 years now. I bought it 2nd hand and well worn.

Some piston scoring and yet the bore didn't look terrible. However, I purchased a NOS OEM, Stihl Piston and Cylinder to use for the rebuild.
The curiosity is how the 2 pistons have different shapes to the cutouts for the transfer ports. I intend to weigh these 2 pistons to compare the original which I think may be grams lighter due to wear, less metal in places, and to get a reading on how each does if I use both in the saw and compare.

That is a series of saws I have never worked with and have no knowledge of what is what on them. My guess would be it might have different makers for each piston. Kolben schmidt, Mahle, Tecomec all have made both cylinders and pistons for Stihl over the years. Any identifying marks on them?