044 question

I'd call dealers around and see if the piston prices are down. If not have someone pick you one up. Can you see any horizontal lines left on the skirts? If you have something really flat get some 80 grit stick on sandpaper and work the cylinder in a figure 8. You can knock a few .003" off in a few minutes.

 

None on the intake side and very few at the top on the exhaust side.

 

I would probably replace it then.

 

Thanks everyone for the well reasoned responses that added insight to your individual decision making process. I will be calling around for an OEM piston. Mostly because an ounce of prevention is worth a pound of cure.

 

Put a straightedge against the piston vertically, on the intake and exhaust sides. When I rebuilt my 044, the original piston skirts were so worn that they curved away from the cylinder wall and a straightedge oriented this way rocked like a rocking horse. The rings were about half their original width, compression was around 115, and it still ran.

 

Separate Question, the cylinder is a KS and I was looking at it. I still have the ruined cylinder off my 12mm 044. It is an early Mahle with the angled fins.
Looking at the casting in the ports on both cylinders the KS seems cleaner and smoother overall than the Mahle. Is the KS thought to be a better cylinder?

 

A lot of people on AS think so, but I haven't seen it objectively substantiated.

 

I also had two 044's at one point, both 10mm, one KS and one Mahle, and cut successive slices off the same tree trunk with them. The KS performed a little better, but it wasn't dramatic and there were too many other differences for it to have been a fair comparison. The KS saw had just had a carb rebuild and its exhaust outlet was significantly larger.

 

The KS early cylinders are a degree or two different on port timing. That's where the performancestors difference is.

 

Port timing is beyond my level of understanding. How does that play out?

 

So there is a difference with the switch to Mahle in 10 mm saws. Was there a change again when they went to the 12mm wrist pin in terms of port timing?

 

I have read in multiple threads on AS, though again without much substantiation, that the angled-fin Mahle cylinders used on early 12mm versions were the same as those used on late 10mm saws.

 

Here you go. First video is a stock KS 044 with freshly rebuilt carb. That saw went to RJames, who's been very happy with it. The saw in the second video had just been rebuilt -- 10mm crank with new bearings installed in an MS440 crankcase, 10mm Mahle cylinder, brand-new Meteor piston. The carb in that second saw had not been rebuilt, and the clutch bearing was worn out (you can hear it tinkling at idle).

Edit: Oh, I forgot, the second saw also has a thinner-than-standard base gasket.

 

Jon ............... one chain was throwing dust while the other is throwing chips.

 

I think that's mostly issues with blurring in the video. It was the same B&C, the first cut looks dustier, and I doubt it got sharper along the way.

 

Chips ? here is a 12mm ms440 with a mahle 10mm jug ,stock porting ,32 inch bar in cedar ,the hopped up saws rev higher with the bar buried


Chips from doug fir ,saw is 461 though ,semi skip square chain i think ? may have been full skip i can't remember .

 

I just watched them again, looks like it could be the sunlight. the second one doesn't have a shadow where the first one does. Both seemed to be close in times too.

 

FWIW, the chain in my videos was just RS3, and had done some other work since it's last sharpening.