044 rebuild

[catch_me-WV]

Well, I finally decided to quit being a lurker here and contribute. I've always found this site to have a wealth of info to answer any questions I've had over the years. So here's a little backstory and my 044 rebuild project.

I joined this site after I bought an 044 at a pawn shop here for $200. At the time I lived a half mile off pavement next to my old landlord's 400+ acres, back in the woods, and used this thing quite a bit and it always ran strong (especially after my muffler mod and a retune, thanks AS!). Fast forward about a year and I was back living in an apartment, but of course I couldn't give up my "nice" saw, so it just sat in storage. Fast forward 3 more years and I'm a homeowner with a few good sized trees, a "hedgerow" of hemlocks that are now 30'-40' tall and were never maintained until I bought the place, and hopefully soon, a functional wood stove (that's another post entirely...).

A few weeks ago I decided that the old girl could use some "freshening up" since the oiler had quit the last time I had it out, the fuel tank that was cracked/bulging since I bought it recently started leaking, and it had a crack in the heel of the rear handle. After doing some research I decided to order an aftermarket tank/handle and new a/v bushings. All went well with the handle swap, and I thought I found the reason the oiler quit because the tip of the wire coming off of the worm gear was broken (see the pic of the clutch side of the case...). I didn't pull the top end at the time because everything looked good enough through the muffler. So I take the saw out to give it a quick test and the oiler still isn't working with the new worm gear (OEM replacement). Back onto the bench it went so I could check it out further... I couldn't feel it by turning the worm gear in the oiler, but once I pulled it out of the saw, I noticed it had a nice "crunchy" feel. Much to my dismay, I also noticed a bit of play somewhere in the con-rod when I tore it back down. So the other night I tore the top end off to check it all out. By the looks of things, she wasn't long for this world! The wrist pin, bearing, and small end are cooked. Interestingly, I can't detect any play there. The play is on the big end, unfortunately. So I ordered an aftermarket crank, meteor piston and rings, main bearings, oil seals, and a gasket kit. As much as I run this thing, I figure the parts should last as long as they're not out of spec too far.

Not sure exactly what caused this kind of failure. There's never been any signs of an air leak. I've always paid close attention to the tune since it got pretty sensitive to weather changes after the muffler mod and I never leaned this thing out much. I always kept it tuned to clean up only after I bear down on the saw a little, so I know it wouldn't have over-revved or overheated to this kind of level. But I did buy it knowing that it had a good amount of hours on it, so who knows what was done to it before me. Funny thing is, it ran fine the other day except the oiler!

Anyways, on to the pictures. I didn't think to get any of the complete saw before I swapped the tank/handle. I've got more pics I'll upload later, showing the cylinder, piston, etc.

 

[happysaws]

Welcome to the site!
Nice pics, BTW...

 

[pioneerguy600]

Looks like a good project saw. Why do you think the crank is bad?

 

[catch_me-WV]

Welcome to the site!
Nice pics, BTW...

Thanks, happysaws. They're just some cell phone pics I took. If I want to get fancy about it, I can always steal the wife's nice new camera... Though I might end up missing some dearly loved body parts if I got 2 stroke residue all over it. lol


Honestly, this is my first time taking the jug off of any 2 stroke, let alone splitting cases. After all the time I've spent lurking here, I'm not intimidated by it though. I'm not too worried about getting it apart, since the crank is shot anyways, so I'm planning on using a non-marring hammer and possibly a home made tool (if need be it'll be easy enough to make with my mini mill). Just waiting on my flywheel puller to get here so I can get started on that. More pictures will be inbound when I get time tonight, and even more once I start pulling it the rest of the way apart.

 

[catch_me-WV]

Looks like a good project saw. Why do you think the crank is bad?

The big end rod-bearing is loose. Oddly enough, that horribly cooked wrist pin wasn't where the crank play was coming from. I wish it was just the small end that had problems...

 

[pioneerguy600]

When you say loose do you mean side to side movement or up and down looseness as in radial slop?

 

[catch_me-WV]

When you say loose do you mean side to side movement or up and down looseness as in radial slop?

Yup, just a touch of radial play. Haven't been able to put a dial indicator on it yet, but it doesn't really matter since it would be a ticking timebomb regardless. More so than an aftermarket crank would be at least, IMO.

 

[Mad Professor]

Welcome to chainsaw forum!

That piston pin don't look too bad to me. What does the bearing and piston bosses look like? Any galling of the aluminum in piston pin bore?

The crank end rod/bearing will have lots of play side to side, that is normal. Radial up/down play is what is bad. Are you sure the crank was/is bad? You might just be able to put new seals in and run the OEM crank if rod and bottom bearings are smooth.

Post some pictures of the oiler parts

P.S. see if you can have a look at a good crank big end rod bearing and see if you are concerned about nothing. They seldom go bad in my experience

 

[catch_me-WV]

Just to help you all understand a bit about me, I do come from a very technical background and am usually far too cheap (read: broke) to pay someone else to do repair work for me and as such have worked with all sorts of electronic, mechanical, and other systems/devices. lol. There have been a lot of hard learned lessons over the years, but all that does is build character and new skills, IMO!

Welcome to chainsaw forum!

That piston pin don't look too bad to me. What does the bearing and piston bosses look like? Any galling of the aluminum in piston pin bore?

Not sure how the discoloration of that wrist pin looks anywhere near ok... but there are ridges built up where those purple rings are and it looks pretty obvious that the pin was turning inside the piston bosses quite a bit. The bearing has serious signs of heat as well (purple discoloration on the thinner parts of the roller cage).

The piston itself has got a couple small scratches I can barely feel with my fingernail. Otherwise, it's just a bit discolored and showing a little wear (probably normal for a saw this age). I'll post more pictures this evening.

The cylinder has nothing that can be felt, just a couple small marks and a bit of wear (nothing that looks bad to me). I'm planning on running some scotch-brite in it with my drill to "hone" it a just a little and help the new rings break in.

The crank end rod/bearing will have lots of play side to side, that is normal. Radial up/down play is what is bad. Are you sure the crank was/is bad? You might just be able to put new seals in and run the OEM crank if rod and bottom bearings are smooth.

I fully understand the difference between lateral and radial play, just to be clear. The rod does have radial play on the big end. My best guess is 1-2 thou. As I said above, I have yet to put a dial indicator on it and I'm not too concerned about doing so since I can feel the play. If it wasn't for that, I would also ignore the fact that the small end is discolored to a bluish purple color, so long as a fresh bearing and wrist pin fit properly in the rod.

The main bearings are fine, but I'm not going to rely on myself to get them off the old crank without damage. Same goes for the oil seals.

Post some pictures of the oiler parts

P.S. see if you can have a look at a good crank big end rod bearing and see if you are concerned about nothing. They seldom go bad in my experience

I'll take a couple shots of the oil pump itself tonight, but I can tell by the feel of it, it's ingested something it shouldn't have at some point (like I described originally, it's nice and crunchy when you run your finger over the gear to turn it).

I don't have a good way to get ahold of a good factory crank to compare this one to without buying one (out of the question at the moment).

 

[pioneerguy600]

Sounds like you have all the bases covered and are capable of pulling off this rebuild, thanks for answering my queries and all the best with your rebuild.

 

[catch_me-WV]

Sounds like you have all the bases covered and are capable of pulling off this rebuild, thanks for answering my queries and all the best with your rebuild.

Thank you! I do try to be thorough in my research and work, so I'll take that as a compliment! Much of the learning I've done on this site has been from your posts. I do believe you've got a lot of experience with this model, based on my searches and reading.

 

[pioneerguy600]

Thank you! I do try to be thorough in my research and work, so I'll take that as a compliment! Much of the learning I've done on this site has been from your posts. I do believe you've got a lot of experience with this model, based on my searches and reading.

Thanks! I have owned and ran the 044`s and MS440`s since around 1990 and laid down a bunch of large swaths of forest with them. I have lost track of how many I have built over the years and now own 9 runners currently with dozens more out there running and making their owners happy. The first saw I bought new in 90 or 91 is still running and its still cutting firewood, I totally rebuilt it back around 07 -08 and it had so many hours on it the paint was almost all worn off. It got etched primed and a new piston with rings,still original cylinder, replaced all rubber parts,seals, gaskets and a carb rebuild. It has run ever since without a problem for a fellow that bucks up more than 10 cord of hardwood each year and does a few lot clearing jobs as well. They are very tough saws, well worth building.

 

[catch_me-WV]

As promised, here are some pictures of the jug, slug, and wrist pin bearing. I'd be tempted to reuse the piston (with a pair of new rings of course) but it's got a scratch or two I can just barely feel with my fingernail, and for the price I'll run a proven aftermarket with caber rings and not worry about it. Like I said originally, I'm definitely reusing the cylinder. I just want to hone it very lightly with scotch-brite or something to help break in the new rings.

Planning on using heat to install the bearings/crank on reassembly. It just seems to be the most logical way to do it without either spending extra money/time to buy or build a specialized tool.

Oh, and for those nerdy enough to think about such things, I do have experience with what differential heating can do... Driving down a straight, smooth paved road on a 15* morning and having my rear glass explode because of a defrost terminal starting to short! Not that magnesium is nearly as brittle as tempered auto glass, but I'll be putting the case halves into the oven for sure (thank god my wife is pretty awesome, lol).

I am also going to figure out some method to vac/pressure test the case after it's done. I've replaced similar oil seals on cars and trucks plenty of times, but nothing this small. I've seen a few homebrew setups on here and will probably just replicate one of them, but I'm not totally decided yet.

 

[catch_me-WV]

Forgot to add that the you can see the discoloration on the wrist pin bearing cage a lot more clearly in person. It can be seen in the photo at the ends of the rollers, just not quite as vividly.

The scratches on the piston are on the intake side (which also has a bit of skirt wear). The bore of the wrist pin holes is also worn more than you can tell in the photo.

Pretty glad I noticed the play in the rod when I did. Don't think it would have ended well if left as it was. Especially since the next job I have for it is ripping 2 8' long by 14"-22" thick spruce logs into some bench planks...

 

[Evan]

Very good looking saw piston and cylinder look normal to me. Also very lottle carbon uild up on exhaust.

I've had little use from special tools on these saws when doing crank bearings.

You seem to know what your doing. If it where me it bump i take and exhaust ports wider . Open up transfers on piston. And maybe run the cylinder gaskettless to bump compression. Depends on squish.

It would be animal

 

[catch_me-WV]

Very good looking saw piston and cylinder look normal to me. Also very lottle carbon uild up on exhaust.

I've had little use from special tools on these saws when doing crank bearings.

You seem to know what your doing. If it where me it bump i take and exhaust ports wider . Open up transfers on piston. And maybe run the cylinder gaskettless to bump compression. Depends on squish.

It would be animal

Thanks. Just wait until I post pictures of the old tank/handle though. She did not look anywhere near that good with it on there.

There was more carbon build up in the ports and combustion chamber when I first pulled everything apart. I already took some green scotch-brite to the it a bit to clean it up and get a better look at it by the time i took those pictures.

I have been considering a light port job while I've got it apart. I need to pick up a couple new burrs and stones for my dremel first. Never have ported anything before, but there doesn't really seem to be much to it. I have done plenty of other fine work with a dremel (you should feel the trigger job I gave one of my black rifles...). Checking the squish is on the to-do list when the time comes. Not sure how much extra compression I want to give it, compared to original. More than once, I've had sore fingers after having the handle ripped from my fingers.

I'm still kinda on the fence with the OE piston because it isn't all that bad. Anybody know what the dimensional specs are supposed to be on a factory 044 piston? If so, I'll take some calipers to mine and see how it compares. I'll probably keep it to play with later, either way.

I also decided to order a few more aftermarket parts, mainly superficial stuff just to make it look a little nicer when I'm done. I do want to keep the oem plastics on top, though. Trying to figure out a fairly easy way to "polish off" some of the oxidation/UV damage on the cylinder cover and air filter cover. I tried some "plastic restorer" stuff for auto body trim and headlights, but it didn't do a whole lot to help.

Oh, and I just realized I never mentioned this before. For anyone looking into the aftermarket tank/handle assemblies, what others have said about the tank vents and control switches is accurate. I bought a new OEM tank vent because the AM part would not allow air into the tank, and reused my original control switch because that AM part didn't want to go to the choke position (even after smoothing/polishing the parts that were getting stuck).

As far as "knowing what I'm doing" goes, I see this more as a testament to what you can do with a decent bit of other mechanical experience and knowing how to search and read. lol! (it also probably helps that I tend to be a really fast learner and an "info sponge," as an old friend put it)

 

[RobbyBoy32]

I had the same problem with the aftermarket tank/handle assembly and control switch. I ended up pulling the AM vent, scrubbing it up real good with some cleaner, then replacing it. Seems to solve the problem it had when it would die after a long cut or some revs in cold weather. Although I kept my aftermarket control switch, I had to really work it for about a month before it goes into the choke position easily. I kept my original switch if anyone needs one. The new aftermarket plastics don't look right on a well worn saw, so I kept the old oxidized ones and "polished" them up with a little bit of oil lolz. They soaked up the oil and are at least matte orange looking now, but I doubt you will ever be able to restore the original color and shine. Some have painted theirs, but I think they still looked kind of janky.

 

[catch_me-WV]

I had the same problem with the aftermarket tank/handle assembly and control switch. I ended up pulling the AM vent, scrubbing it up real good with some cleaner, then replacing it. Seems to solve the problem it had when it would die after a long cut or some revs in cold weather. Although I kept my aftermarket control switch, I had to really work it for about a month before it goes into the choke position easily. I kept my original switch if anyone needs one. The new aftermarket plastics don't look right on a well worn saw, so I kept the old oxidized ones and "polished" them up with a little bit of oil lolz. They soaked up the oil and are at least matte orange looking now, but I doubt you will ever be able to restore the original color and shine. Some have painted theirs, but I think they still looked kind of janky.

Yeah I'm not digging the paint idea, myself. I mean I could buff the hell out of it and polish it up, but I'm not going for "new" looks anyways. I just want to clean it up a bit more. Though, with it being cleaner and better looking I won't have quite as hard of a laugh when some joker tries to talk smack with their farm boss... Had a couple good laughs before when those folks saw what this "old piece of junk" would do with a 24" bar in a nice big chunk of red oak (even though it wouldn't have been quite so bad if they knew how to sharpen a chain)...

 

[catch_me-WV]

Got my flywheel puller and the meteor piston kit today. Actually my crank kit has been sitting at the post office since yesterday, but the folks that work there are useless... They won't deliver to most houses is my town, so we are forced to use PO boxes (at least they're free). The trouble is, they close before I can make it pretty much any day except Saturday. Checked my box yesterday and had one of those stupid yellow slips even though almost every parcel locker was empty. So I wrote a note on the slip asking them to put it in a parcel locker and put it far enough in the box where it was sticking out the back side. Got there today, knowing I had 2 other packages (one of which was small enough to fit in my box). Well, the slip was still in there, but so was a key. I went to that locker and opened it up and found my piston kit and 2 packages addressed to someone else (with their po box addresses on the labels and everything), but no crank kit! And these incompetent fools wonder why nobody likes to deal with them... Anyways, rant over...

Got the flywheel pulled with no problem, drove the dowel pins out with a punch, and pulled the case screws. The case split apart easy as could be with nothing more than a couple taps with my non-marring hammer on the clutch side. That bearing stayed in the case. It took a bit more effort to tap the crank out of the other side, but that's probably because the bearing stayed on the crank. I can say I'm glad I got replacement bearing, too. The originals don't feel too great now. Next task is to remove the clutch side bearing from the case. I tried to drive it out with a socket, but made no progress without needing to hit it harder than I am comfortable with. Since I don't have a press, I'm thinking about cleaning that side up and heating it up before trying again, since I'm pretty sure magnesium has a much higher thermal expansion rate than the steel of the bearing. I suppose if it want to be a big enough pain, I'll just pull the vise off my mini mill's table, break out the work holding kit, and mill a slot through the outer race. Anybody have any other ideas than these that can be accomplished without a press or any special tools?


Had to take a quick picture of this since I do love having the little chinesium thing around. Not exactly a production machine, but for a cheap, small, and fairly portable machine, it does work pretty well if you take your time. It does work great for making some very noisy and mean looking "ghosts" too!

 

[pioneerguy600]

Heat your case half up in an oven, 350 to 375F and then slap/slam it down hard on a hard wood surface, the bearing should just fall out. Most I ever had to do was tap it with a 1" wooden dowel and hammer.