stihl 044 top end question.

[rupedoggy]

Looks savable to me. Hit it with muratic acud the a brake hone very quick and toss a piston in it. My 10mm 044 was string in stock form

Evan I don't usually disagree with you but how can you tell the cylinder will be salvagable by looking at the piston? That is one of the worst pistons I have seen for melting. Look above the ring. There is missing aluminum. Look at the rings. They are locked into the piston halfway around. There are lots of score marks in the rings. They may have gone through the plating. I often wonder how a guy got the saw to run that long, to do that much damage.

 

[Jacob J.]

I often wonder how a guy got the saw to run that long, to do that much damage.

That's a scenario where the operator just has to ignore the smell of burning aluminum, silicon, and melting plastic.

 

[nmurph]

That's a scenario where the operator just has to ignore the smell of burning aluminum, silicon, and melting plastic.

...and staying hard on the trigger. They won't idle with a piston in that condition.

 

[PaulW]

I bought the saw a week ago knowing it had low compression, but it did run. I was hoping it was just rings...any advice as to cause of death to avoid this from happening again?

 

[026 fanatic]

Hones for cylinders.

Looks savable to me. Hit it with muratic acud the a brake hone very quick and toss a piston in it. My 10mm 044 was string in stock form

As a tech, I've looked into the brake hone route. An old saw mechanic put me onto the use of 120 grit flap hones. Turn oversized flap hones down to useable size by chucking in drill and running in reverse against coarse abrasive. Turn to where it can just be forced into cylinder. Lube with transmission fluid, and graphite as a binder. Turn drill to forward and cycle within the cylinder. Keep moving hone up and down constantly. Turn until smoot. Check with light. Once all traces of piston are gone from cylinder, immerse in hot soapy water. Do not clean with gas, boiling them out is actually best.

 

[026 fanatic]

Cause of failure

I bought the saw a week ago knowing it had low compression, but it did run. I was hoping it was just rings...any advice as to cause of death to avoid this from happening again?

Classic lean burning situation. Possible causes: bad fuel, air leak, faulty fuel line, restricted high speed jet. Check fuel Line first, then impulse line, then carb. Then check crank seals. Where I work, legislated moonshine keeps me in work replacing fuel delivery components almost constantly.

 

[stihl038x2]

You should stay away from the big bore kit, there are issues with the 10 mm.

I have two 044's built on 10mm pin cranks , with a ported "slant fin" OEM jugs & they are absoslute beasts, so don't shy away from the 10mm pin saws.

Steve

I have also owned a 10mm 044. I dont really understand what your saying, they do run great, but theres no Big bore kit for them without some serious modifications, and that is all i said.

This is the part of the quote I was making reference to. My 10mm saws are ported very strong & they have not let me down as of yet.
I also jig ground out the rod of another to suit the 12mm pin & put that crank in a pipe saw which has held together, so I'm not afraid of the 10mm pin cranks. Maybe I just got lucky ?

<iframe width="420" height="315" src="http://www.youtube.com/embed/awgz06OBFiY" frameborder="0" allowfullscreen></iframe>

Steve

 

[rupedoggy]

This is the part of the quote I was making reference to. My 10mm saws are ported very strong & they have not let me down as of yet.
I also jig ground out the rod of another to suit the 12mm pin & put that crank in a pipe saw which has held together, so I'm not afraid of the 10mm pin cranks. Maybe I just got lucky ?

<iframe width="420" height="315" src="http://www.youtube.com/embed/awgz06OBFiY" frameborder="0" allowfullscreen></iframe>

Steve

Wow that is interesting. If I understand you took a rod for the 10mm pin and "jig ground" (whatever that means as I am no machinest) and fitted a 12mm pin. Those rods are super hard and the bearing rides on the pin and inside the rod hole. How did you get it smooth enough and round enough? Also there does not seem to be much material to do that. How thick were the walls of the top of the rod?

 

[stihl038x2]

Wow that is interesting. If I understand you took a rod for the 10mm pin and "jig ground" (whatever that means as I am no machinest) and fitted a 12mm pin. Those rods are super hard and the bearing rides on the pin and inside the rod hole. How did you get it smooth enough and round enough? Also there does not seem to be much material to do that. How thick were the walls of the top of the rod?

With access to a $375K + machine & some "free time" on the night shift you'd be surprised how round, smooth & straight a hole can turn out I wouldn't do this for an all day runner/worksaw because you wind up removing the "case" (hardest part of the rod), & longevity will most definately be compromised. As far aswall thickness remaining, I don't remember what it was & how much remained . If she blows, then she blows, it was a blast to do and thats all that counts :msp_smile:

Anyhow back to the OP, I'd clean up that jug port it & put in a Meteor 10mm piston then run it like you stole it !!

Steve

 

[Jacob J.]

If you can't get your jug cleaned up then I or others probably can get you into a good used OEM jug.

 

[imagineero]

I have two 044's built on 10mm pin cranks , with a ported "slant fin" OEM jugs & they are absoslute beasts, so don't shy away from the 10mm pin saws.

Steve

+1 on that. I've owned a few 044's over the years, both in 10mm and 12mm as well as 441's. The 10mm gets a bad rap for no real reason. In my opinion the 10mm is the more desirable saw as a work saw. If they have equal compression and good carbs, the 10mm versions just seem a bit more eager.

Shaun

 

[PaulW]

Ok so Im going to try to hone the cylinder clean. Change the piston and try again.

 

[stihl038x2]

Ok so Im going to try to hone the cylinder clean. Change the piston and try again.

I would try acid instead of a hone. The hone runs the risk of removing the plating . Do a search , there are many dicussions & how to's on the site.

Steve

 

[nmurph]

Ok so Im going to try to hone the cylinder clean. Change the piston and try again.

You don't want to hone the cylinder clean. The Nikasil coating is very thin, and while it is very hard, you can cut through it with a hone. Get some muriatic acid and a q-tip. It will bubble the aluminum transfer off. It is somewhat slow go; heating the cylinder in the oven will speed the process. I only hone when I am finished to make sure the port chamfers are smooth.

 

[PES+]

Not good to use a power tool for removing aluminum transfer but you can use hand sanding after the acid to clean up.

Very few sand papers are hard enough to actually cut the mikasil or even the hard chrome plating so there is no worry about going out of round in the bore.

 

[Jacob J.]

+1 on that. I've owned a few 044's over the years, both in 10mm and 12mm as well as 441's. The 10mm gets a bad rap for no real reason. In my opinion the 10mm is the more desirable saw as a work saw. If they have equal compression and good carbs, the 10mm versions just seem a bit more eager.

Shaun

The 10mm 044 gets a bad rap due to the weak big-end rod bearing. I worked for a big logging company in high school and they used the 10mm 044s on landings. They were only getting about 4 months out of each saw before the big end rod bearing would blow. This was while running 32:1. Landing conditions are about the hardest a saw will run in though apart from milling.

There was a reason that Stihl upgraded to the 12mm wrist pin and larger big end rod bearing. I agree, the 10mm saw is a fine runner and those early cylinders had good port timing.

 

[lone wolf]

Exhaust side. Intake looked almost new. Cylinder matches tbe piston precisely.

Was it straight gassed? check the rod for up and down play. What about the crank side bearings left and rt are they tight how bout the crank seals:msp_wink:?

 

[SkippyKtm]

You don't want to hone the cylinder clean. The Nikasil coating is very thin, and while it is very hard, you can cut through it with a hone. Get some muriatic acid and a q-tip. It will bubble the aluminum transfer off. It is somewhat slow go; heating the cylinder in the oven will speed the process. I only hone when I am finished to make sure the port chamfers are smooth.

Great post nmurph, that's exactly what I do and it works.

Its worked for me with better than 90% success rate, you can save a lot of cylinders with this process. I've posted this video from Roncoinc (thanks!) on How to use the muriatic acid (muriatic acid also known as Hydrochloric acid, only attacks the smeared on aluminum and not the original Nikasil plating).
Here's the vid:

<object width="640" height="360"><param name="movie" value="http://www.youtube.com/v/Fr_Odf9yO4g&rel=0&hl=en_US&feature=player_embedded&version=3"></param><param name="allowFullScreen" value="true"></param><param name="allowScriptAccess" value="always"></param><embed src="http://www.youtube.com/v/Fr_Odf9yO4g&rel=0&hl=en_US&feature=player_embedded&version=3" type="application/x-shockwave-flash" allowfullscreen="true" allowScriptAccess="always" width="640" height="360"></embed></object>

 

[GASoline71]

I am LOLing at the "10mm 044's have issues". I have 2 of them... both built in '92 or '93. Both have the large port stock exhaust and both cylinders are stock. They simply rip... Prolly my all time favorite saw to fall with. Been thinkin' about havin' one of the cylinders "cleaned up a bit", and see how it does...

Nowthen... the BB kits... they are just a bunch of junk if ya ask me... You couldn't pay me to use one.

Gary

 

[lone wolf]

I am LOLing at the "10mm 044's have issues". I have 2 of them... both built in '92 or '93. Both have the large port stock exhaust and both cylinders are stock. They simply rip... Prolly my all time favorite saw to fall with. Been thinkin' about havin' one of the cylinders "cleaned up a bit", and see how it does...

Nowthen... the BB kits... they are just a bunch of junk if ya ask me... You couldn't pay me to use one.

Gary

Stock is best I believe!