Stihl 044 questions, new piston required.

[freeasaburt]

Your piston has a lot of miles on it although not scored badly it does have a good bit of damage on the intake side from a bad filter allowing debris through it, a new piston and clean up the cylinder will give it a good long lifetime with proper maintenance. A wrist pin can be reused if it has not been blued badly from heat, I like to use a new bearing but have reused several with no issues.

Debris was my guess too, thanks for confirming that. I already have a new air filter, hope it's a good one.
Now I have to order some parts ... piston, carb kit, gaskets, the little bent hose for the tank vent, probably a cover for the pull cord side, etc. etc.

 

[lone wolf]

Debris was my guess too, thanks for confirming that. I already have a new air filter, hope it's a good one.
Now I have to order some parts ... piston, carb kit, gaskets, the little bent hose for the tank vent, probably a cover for the pull cord side, etc. etc.

OEM all the way! No China junk!

 

[chilipeppermaniac]

Fill the recess in the back side of the seal with grease. I guess I left out some info there.

Thanks stihltech, this is what I presumed, but wanted to verify.

 

[huskihl]

I think the crank is about done. I would do whatever is required to put those parts back in it the way they are and run it a little bit and see if it has a rattle

 

[lone wolf]

I think the crank is about done. I would do whatever is required to put those parts back in it the way they are and run it a little bit and see if it has a rattle

Can you tell if it is up and down play or side to side from that video clearly? If so the OP needs to check it correctly.

 

[huskihl]

Can you tell if it is up and down play or side to side from that video clearly? If so the OP needs to check it correctly.

No not really. I just saw him leaning it more than what they normally do. He wasn’t just sliding it left and right. That rod was moving on an angle

 

[chilipeppermaniac]

Debris was my guess too, thanks for confirming that. I already have a new air filter, hope it's a good one.
Now I have to order some parts ... piston, carb kit, gaskets, the little bent hose for the tank vent, probably a cover for the pull cord side, etc. etc.

I think the crank is about done. I would do whatever is required to put those parts back in it the way they are and run it a little bit and see if it has a rattle

Hard to tell in the picture, but one area to be concerned with is on the big end. If there is any blueing discoloration from the possibility of the bearings getting hot and heating the crank too, this can cause the unwanted up and down play that has been mentioned by others.
Also, from the amount of scuffing/scoring of the piston, how much free play is in that cylinder even if things are cleaned up and new rings installed etc. How thin are the piston skirts?

 

[lone wolf]

No not really. I just saw him leaning it more than what they normally do. He wasn’t just sliding it left and right. That rod was moving on an angle

I kinda saw that too but pics and video can be deceiving at times. He needs to hold it dead centere perfectly straight and pull it up and down and report back here if there is any up and down play. I know you know this its for him.

 

[freeasaburt]

I think the crank is about done. I would do whatever is required to put those parts back in it the way they are and run it a little bit and see if it has a rattle

I ran the saw when I bought it. Idle way too high but it started up without issues and I didn't hear anything weird or unusual. Easy to start, to the point where I wonder if it has enough compression. (not sure, never used a 044 before).

No not really. I just saw him leaning it more than what they normally do. He wasn’t just sliding it left and right. That rod was moving on an angle

It does move at an angle indeed. At the top of the piston, the difference is about 3mm.

I kinda saw that too but pics and video can be deceiving at times. He needs to hold it dead centere perfectly straight and pull it up and down and report back here if there is any up and down play. I know you know this its for him.

I don't notice any up and down play. The only play there is, is that I can move the con rod laterally a bit, and the angular play I just described.

Would that bearing need to be replaced?

 

[huskihl]

I ran the saw when I bought it. Idle way too high but it started up without issues and I didn't hear anything weird or unusual. Easy to start, to the point where I wonder if it has enough compression. (not sure, never used a 044 before).


It does move at an angle indeed. At the top of the piston, the difference is about 3mm.

I don't notice any up and down play. The only play there is, is that I can move the con rod laterally a bit, and the angular play I just described.

Would that bearing need to be replaced?

If you didn’t hear it rattling, you’ll be all right for a while. That bearing isn’t really replaceable. You would need a new crank

 

[freeasaburt]

Ah. Well, seeing that I'm not looking forward to trying a case split, and also the fact that oem cranks cost quite a lot, I think I'm gonna try to run it with a new piston. It has been a nice learning experience up 'til now, if I get a saw out of it that runs well for a couple of years I'm satisfied, and can consider a complete rebuild later.

 

[pioneerguy600]

Can you tell if it is up and down play or side to side from that video clearly? If so the OP needs to check it correctly.

I had missed that vid until now but after watching it I can see there is a lot more tip sideways than the big end sliding laterally , that is a lot of slack but it might hold together for a few more hours, no piss revving though.

 

[ZeroJunk]

Well, I put a Chinese crankshaft in an 066 for a tree service guy probably 8 years ago and he is still using it.

And, on top of that the Platinum Stihl dealer he had been taking it to had kept cranking down on the ignition screws until he stripped them out when the problem was the bearings were bunch up and the flywheel was beating the crap out of it. It was one of those three leg coils. Can't remember what I tapped it to, something SAE. 12-24 I think.

Nothing for a pro faller or anything. But, an occasional big yard tree for a tree service...
I charged him what the parts cost and told him it was an end of driveway guarantee.

Still using it.

 

[chilipeppermaniac]

I ran the saw when I bought it. Idle way too high but it started up without issues and I didn't hear anything weird or unusual. Easy to start, to the point where I wonder if it has enough compression. (not sure, never used a 044 before).


It does move at an angle indeed. At the top of the piston, the difference is about 3mm.

I don't notice any up and down play. The only play there is, is that I can move the con rod laterally a bit, and the angular play I just described.

Would that bearing need to be replaced?

Let me ask about the compression. I know the saw is apart now. But without a compression tester, you can try hanging the saw and bar by the pull cord and watch how fast or slow it drops. Fast drop, low compression, slow drop/ decent bet it has good compression.

 

[freeasaburt]

I found a crank, supposedly oem, for €116... Tempting... If it turns out to be fake I can always send it back.
I think it will be a 'bare' crank, not unlike the piston I can order, so additional required parts can drive up the price.
However, I lack the knowledge/skills to split a case... Gonna check youtube and see what tools I would need etc.
Recommendations welcome, obviously! A good flywheel puller, for example.
Thats a lot further than I wanted to go but it could be a nice learning experience, and it sure would be great to get it running nicely.

Also, I found this (probably very Chinese) pressure tester, on this cheap german chainsaw parts site... Any idea if it would be actually useful? I don't even know how exactly it should be used. https://shop.saegenspezi.de/compres...atible-with-chainsaws-with-M14-and-M18-thread

 

[pioneerguy600]

I found a crank, supposedly oem, for €116... Tempting... If it turns out to be fake I can always send it back.
I think it will be a 'bare' crank, not unlike the piston I can order, so additional required parts can drive up the price.
However, I lack the knowledge/skills to split a case... Gonna check youtube and see what tools I would need etc.
Recommendations welcome, obviously! A good flywheel puller, for example.
Thats a lot further than I wanted to go but it could be a nice learning experience, and it sure would be great to get it running nicely.

Also, I found this (probably very Chinese) pressure tester, on this cheap german chainsaw parts site... Any idea if it would be actually useful? I don't even know how exactly it should be used. https://shop.saegenspezi.de/compres...atible-with-chainsaws-with-M14-and-M18-thread

That Comp tester would be useless as it has no schrader valve in the fitting that screws into the sparkplug hole. For small engines like chainsaws the comp testers need a valve at the end and that valve is a special soft return spring type, white in color.

 

[ZeroJunk]

https://www.ebay.com/itm/3253580361...:g:hQwAAOSwVmtjMXbF&amdata=enc%3AAQAHAAAAoHk8

I use one like this. I made one with a heavy piece of angle iron by drilling a couple of holes for the bar studs and welded a nut over the end of the crankshaft. Marginal at best. These work fine.

 

[stihltech]

If the rod has no up and down motion on a straight up and down pull, it is ok. Check the side bearing cages for missing parts. NO play in the crank side bearings.
The piston wear is from age. Replace it. The cylinder looks OK. Give it a finish with 400 wet or dry sandpaper to seat the rings. Vac and pressure test after repair to verify tightness.
The excess wear will let mixture by the ports and knock the power down. That is why a new piston runs so much better.

 

[freeasaburt]

Now I'm sort of confused whether I should buy a crank or not
Are the side bearings the ones on the clutch and starter side, respectively?
I've been cleaning up the cylinder with scotchbrite, as I didn't want to take any risk, scratch-wise. It looks a bit better already, don't think I will be able to remove all visible lines but I can't feel them, in any case.

 

[freeasaburt]

Let me ask about the compression. I know the saw is apart now. But without a compression tester, you can try hanging the saw and bar by the pull cord and watch how fast or slow it drops. Fast drop, low compression, slow drop/ decent bet it has good compression.

Yeah I know about that test, will try it later. I expect it to drop quite slowly; maybe I underestimate the compression as the previous saw I bought, an 064/660 hybrid, has huge compression, to the point where I can barely start it. The thing has a very strong ambition to rip my arm off