Preparing to port first saw - which one, and what method?

[MG porting]

Ok, my wife was out of town and I had time, so I ported my older 266 last night. It had the SE Mahle cylinder on it, labeled 50ZN11. I had an extra XP cylinder (50ZN13), so I decided to do that one.

Without base gasket, the numbers for the XP cylinder were:
Exhaust: 106
Uppers: 122
Intake: 70
Squish: .017"

I took down the ridges on the lower transfers and smoothed them out, being careful not to go deep towards the case. I removed some material inside the transfers behind the "bridge" to skinny them up as well.

Raised exhaust roof slightly to 102, really widened it up and funnelled it outwards. Exhaust roof was pretty flat from the factory, so I followed the factory contour. Polished everything up very nicely afterwards with aluminum oxide stone, then emery paper in a mandrel, then polishing compound and a felt wheel. Port matched muffler and gasket. Muffler was already modded.

Lowered intake to 78, widened, and cleaned up. Left it rough.

Went over edges with diamond ball, and then ball honed both directions.

Advanced timing 0.025" off the key.

Now it's sitting at:
Exhaust: 102
Uppers: 122
Intake: 78
Squish: .017"

I heat cycled it a couple of times, and then put it in the wood this morning. Pulled a 25" full comp with low rakers in some 20" green pine with way more power than before. Throttle response is way better. Tunes at WOT @13.2k. Holds 9.5k in the cut. Sounds great.

I'm happy. I used the full-circle piston that was in it, but I think I will tear it down and replace it with the windowed Meteor piston sometime in the near future. I'll share some pics then.

I think I will use this recipe for the 266 build that I am working on in the other thread.

I would leave the full circle piston in it but that's just me glad it worked out for you tho now you'll be finding saw to port just because

 

[mainer_in_ak]

Dang, nice work! You chose the right saw to port. The older dual port 67 cc saws are dirt cheap, and when woods ported at home, slap all of the current 60 cc saws silly. Parts are cheap and readily available.

I too started porting on the older 67 cc saws, and they sing a sweet song! They out-cut my stock jonsered 2172 and the neighbors stock stihl 044.

The 67 cc saws were 1/4 the price of my more modern 70 cc saws. Old, cheap woods ported 67 cc saws actually resulted in me quitting 40-50 cc saws. Gave em all away.

Never heavy in weight, and ideal for everyday cutting and most typical wood. Most smiles per dollar.

 

[mainer_in_ak]

Ok, my wife was out of town and I had time, so I ported my older 266 last night. It had the SE Mahle cylinder on it, labeled 50ZN11. I had an extra XP cylinder (50ZN13), so I decided to do that one.

Without base gasket, the numbers for the XP cylinder were:
Exhaust: 106
Uppers: 122
Intake: 70
Squish: .017"

I took down the ridges on the lower transfers and smoothed them out, being careful not to go deep towards the case. I removed some material inside the transfers behind the "bridge" to skinny them up as well.

Raised exhaust roof slightly to 102, really widened it up and funnelled it outwards. Exhaust roof was pretty flat from the factory, so I followed the factory contour. Polished everything up very nicely afterwards

Advanced timing 0.025" off the key.

Now it's sitting at:
Exhaust: 102
Uppers: 122
Intake: 78
Squish: .017"

Pulled a 25" full comp with low rakers in some 20" green pine with way more power than before. Throttle response is way better. Tunes at WOT @13.2k. Holds 9.5k in the cut. Sounds great.

9500 rpms in pine is a bit slow. Check the compression, that squish is a bit tight and might be fighting yah.

Pull the cylinder and raise the exuahst roof a couple more degrees. Should gain some rpms in the cut.

 

[huskihl]

9500 rpms in pine is a bit slow. Check the compression, that squish is a bit tight and might be fighting yah.

Pull the cylinder and raise the exuahst roof a couple more degrees. Should gain some rpms in the cut.

It needs the transfers raised 4° in order to get those RPMs back.

 

[jacktheripper]

It needs the transfers raised 4° in order to get those RPMs back.

Stacking cutting disks OK?

 

[jacktheripper]

I tuned it a bit leaner, still 4 stroking, holding more like 10.5k while self feeding low rakers now.

 

[Woodwackr]

I have a bunch of cleaned 266 carcasses if you need more, lol

 

[huskihl]

Stacking cutting disks OK?

I think everybody that has ever ported a saw has done it once or twice. I have cut the line I wanted and then smoothed it out with a round ball in a straight hand piece. Just be careful of the plating next to the port