044 10mm for my neighbor, Eric

[NateSaw]

I forget who said on here that the 026 was a gateway drug... Anyway, my best buddy Andrew, (who's 038 accidentally became a magnum), told my neighbor Eric I'd look at his saw. It's an old ('88?) 10mm 044. It had an Intermittent hard/no start issue and he wanted a general going over/cleaning. Eric told me how he wound up with the saw and how much he loved it. The tank vent was missing something but in my lack of knowledge I didn't know what. Neither did either of the dealers I use. Anyway, I removed the water from the tank, put a fresh filter on it, and voila... It fired and ran well, everytime.
Before asking around here, I temporarily rigged up a cap with a slit to reduce the amount of fuel leakage.
Eric came to get the saw and we talked for hours about saws and how he'd love to have a longer bar on this this thing so he could, as bbrs says, stand up and buck. I explained that more power would make a longer bar possible. In that conversation I showed him threads on here and told him about my adventures with my 026 and how welcoming and supportive, if not at times comically ball busting and patient the fellers on here are. I said I could attempt to port his saw and make it rip a little harder and he wanted that. So, I dug in. As usual, @drf256, @Mastermind, answered questions and I've had wonderful coaching along the way. As busy as all of you guys are, it continues to amaze me how willing you all are to break off time, and share your experiences. In ways, I have moments where I feel I have no right to be cracking into these vintage Stihl's. I'm working on an anemic budget with limited tools. And worse, no experience. As you all basically give me the answers to the test, I can also see how there's a but of a Mr Miagy approach to your teaching, helping this dense mind of mine slowly process the relationships of each ports timing in the big picture of the cycle. So, thank you. Thank all you badass fellers on here. Lemme try and get this thread caught up to where I am. Bear with.

 

[NateSaw]

Took down timing numbers, probably 3 times. I'm still lacking consistency with the wheel...
32thou squish
106 exh
126 transfers
72 intake

 

[NateSaw]

AL gave me a formula to start with...
Delete gasket, bring exh up to 102*, widen, shave 25thou off flywheel key.

 

[NateSaw]

Filed the key, sanded the squish, then,

Set some lines to ignore, and some to follow...

Raised, widened, then polished the exh.

 

[drf256]

Looks good. For a longer bar 044, 101-102 would work well. They do very well with a cleaned up band and squish adjust alone. Raising the exhaust back up should add some punch.

 

[NateSaw]

The muffler. Closed off stock port. Welded in stainless, slash cut facing front cover to absorb some sound.

 

[NateSaw]

I was going to use the spark screen, relocated to the pipe. Would've been ideal to have an arrester. But, I didn't trust that the screen may come unraveled, or the God forsaken spring clamp could fail. Thought the wiser or metal making it into the exhaust port.
So, I deleted this treatment.

 

[NateSaw]

Went to work on some signature cleaning, stripping, and dress up. Polishing mag components is a cheap way to give these saws a vintage patina. It does require maintenance though. But it's not bad. Recoil cover needs an occasional application of mothers. Clutch cover seems to hold polish better due to bar oil. Seems logical to polish parts that get chipped when powdered. I might do the whole case on this saw... Stay tuned for why..

 

[NateSaw]

Having done the basics, squish sanded, key filed 25 thou, exh port raised (lacking practice and accuracy, I came in at 101*), muffler modded, max flow filter installed (minus that God awful honky assed airbox that comes with it), I decided to assemble, and see how it ran.
First impression... I had to jack the low screw out (rich) way too far to get it to start. Once it did, the piss revving commenced. This thing was awake. Snappy af! Sounded beautifully balance between intake and exhaust. But... It wasn't making smoke. I ran it over to my best buddy's and we took turns snapping the throttle and giggling like children. But I didn't like that it needed so much fuel adjustment, and still, really wasn't smoking. Should've been fluffier than a stuffed bear. I had an intuition that more porting was needed.... I ran the new numbers by Al and he said for sure it needed less blow down, earlier intake. What a blessing he and I wanted me to pull the jug again.... What I saw was horrifying....

 

[NateSaw]

Somehow... In spite of having this case covered, I introduced a metric fk ton of depris and contamination while grinding and welding... My space is confined, but I thought I was conscious and taking measures... Rookie mistake abated by good coaching. The good news on the piston, was also bad news... It's what I get for not asking around here... The meteor slug for these 10mm 044's, is milled from the 12mm blank. The wrist pin bearing has room to do the walk of shame all over the pin... So.. On top of discovering the contamination, and learning the best trick for really cleaning these things out, I found axial play in the piston...

 

[NateSaw]

@drf256 gave me some new goals with timing... I was @ 101*exh,126* transfers, and 70* intake. Al told me to bring the transfers to 122* and the intake down to 74-78*. Again, I didn't ask anyone how they map intake.. Al said I could nip the skirt if that would be easier, but I wanted to do the port. I figured the only way to lay out the intake, was to bring the piston to the desired degree on the wheel, then scribe it through the port, then measure the distance from the scribe to the bottom of the skirt, transfer that measurement to the port floor, and layout to grind. During the scribing, that's when I discovered axial play. The piston was doing the twist in the bore. Alot. I was concerned about both the pin play, and big end. Al then told me about the meteor slug issue. I had my mark though, made the decision to continue porting, and would go back to the oem slug and pin on reassembly. Anyway, the oem slug was 7.7g lighter than the meteor, and the oem pin was tapered and lighter too. So I got to cutting the ports, got a new oem pin bearing, and washed the case and all parts in mineral spirits. Mineral spirits should be called miracle spirits. Best cleaning I've ever seen. All particles were in suspension after some sloshing, and poured right out of the case. Followed by jamming some fresh paper towels against the crank weights, and rotating through the case... A rewarding squeek confirmed an immaculate cleaning.
Made my mark, inserted 2 rings and used piston to push to just above mark. Made a layout line, then brought the center of port down to line. Made lines for width guides, then massaged from center to those...
Blended all to Port inlet, then roughed up with 80 grit, finished with scotch Brite to knock off any loose... I didn't want another contamination issue. Mind you, my goal in layout was to hit 78*...

 

[NateSaw]

My new Chineseum 90* hand peice... I hadn't tried it yet... It needs to be turned in the lathe to fit the cable drive. Too big. Also, I need a collet for I think 4mm bits... So to my disappointment, I had to use the cut off wheel method on the uppers.

 

[NateSaw]

I'm embarrassed to post these. You guys cut beautiful uppers. This is shiot. But, it achieved the timing...

 

[NateSaw]

I did use the ring method to raise the uppers. However, I did follow the slight upward tilt these transfer had oem. I didn't want to reinvent what they did, just copy and raise.

 

[NateSaw]

Reassembled, here are the new, final numbers :
Squish @ 17-18 thou.
I found that the piston sanding method wasn't ideal due to differences in squish band thickness, coupled with piston play in bore... I used 220 grit, not too aggressive. It seems the slight tilt of the piston, combined with offset in material, allowed the thin portion of the band to sand away more than the thick. Makes sense.
Exhaust @ 101.5
Uppers @ 120
Intake @ 79.5
Yes, the exhaust measurement changed. No I didn't epoxy the port lol. I'm still working on accuracy and consistency with the wheel. Yes, I overshot the mark on the intake...

 

[NateSaw]

Backtracking a bit to the rod... Before assembly, I scrutinized the rod bearing in a truly ghetto way. I know there must be a good setup for getting a dial indicator on these things to confirm or deny play in the bearing / rod/ crank. It seems well worn in, but no matter how I tried I couldn't produce vertical play in the bearing. I could twist it and maaaaaybe sorta kinda feel a fraction of a c hair of axial... I don't know. At the end of the day, my intuition, coupled with Al's caution, is what I'm going to have to listen to. It's an '88 044 10mm vintage grenade that now runs like a spruced up 462, with a bad knee.... More on this later.

 

[NateSaw]

I wanted to protect the max flow filter from pant legs, stickers, and what have you... I didn't want anything on this unti to have to be babied... But I refused to ugly this beauty up by running that pos cover that comes with these filter. I had to somehow push the stock cover back to accommodate the big foam...


Thanks to the two 461's I have laying in wait, I had a donor for the solution. I used the velocity stack, and the longer studs... Took one of his stock studs, cut it to length, and cut threads for the center stud...

 

[NateSaw]

I broke out the ss mesh again, and voila. Al tells me these horns are unobtanium, and bring real money. I couldn't think of a better place to donate than my buddy Eric's saw... Icing the cake I guess. Can you believe the intake became more visceral sounding? Sounds really tuned. But.... Back to what matters....

 

[NateSaw]

All said and done, this saw rips. It's phenomenally smooth, super snappy, and somehow, even having overshot the mark on the intake, has enough torque to pull the 28" bar. The rings haven't seated at all yet, so there will be more torque as the compression raises. That has been my experience with the Ole ohh too sicks. Bottom line though, I need a crank. I cannot trust the rod bearing. I think I can hear it, but I'm not certain. I'd like to find a good used 12mm crank, slug, and pin. I have the bearing, as hl supply sent me one for a 12mm. (I may have screwed up and selected a 12 when Eric ordered parts). I want to get the best new crank bearings and seals. Any and all help here would be appreciated. Where to go for these things, if anyone has any of them in stock, or laying around. I won't feel right giving this man his saw back, worrying about that rod bearing destroying his case. I want him to be able to run it as though it's a new saw. Worry free.

 

[NateSaw]

More about the bar...
Eric wanted a sugi... But they're hard to find again. He thought that's what he ordered from amicks, but this is what he got. Apparently it's a tsumura. Al and I were wondering if maybe they are factory seconds... Looks great to me. Except for stupid name... They come in cheaper than both the sugihara and tsumura bars.... If anyone wants to know.