MS260 port job

[Blinky]

Can i just whack it somewhere with a bandsaw and glue it back together? That should knock off about .050".

 

[Al Smith]

I suppose you could make a head for it . I dunno a person might be able to cut the cylinder loose and bolt it back on somehow but it would be a lot of work .

I've got a 29 cylinder in the shed ,let me investigate .

 

[woodworkingboy]

Wondering if there might be another piston that you could swap for the
stock one on the 029, to raise compression? It would undoubtedly require some machining to get the right squish.

 

[Blinky]

I suppose you could make a head for it . I dunno a person might be able to cut the cylinder loose and bolt it back on somehow but it would be a lot of work .

I've got a 29 cylinder in the shed ,let me investigate .

Al... hey Al, stop, don't go out there! I was just kidding.

 

[woodworkingboy]

Don't worry Blinky, that's just an excuse to go out there to get more beer.

 

[Al Smith]

Oh it becomes a big mystery after a while unless you have about a warehouse full of parts . Especially if you are talking about windowed pistons .Actually I have no idea if a 29 has a window or not ,never tore one down .I was just assuming because most Stihls do .

 

[Al Smith]

Oh I can't see in the shed anyway .I might injure my person tripping over all that junk in the dark .

 

[Blinky]

Oh I can't see in the shed anyway .I might injure my person tripping over all that junk in the dark .

I would hate to be responsible for that.

 

[Al Smith]

Don't worry Blinky, that's just an excuse to go out there to get more beer.

No beer tonight ,gotsta work in the morning after being in semi retirement for three weeks . It was nice while it lasted .

 

[Dave Shepard]

I've got my new seals, Hondabond 4, just waiting on the bearings. I polished up the intake and exhaust ports, but not sure I really did any good. I can go a lot wider on the intake I'm sure, but the way the exhaust is, it is pretty thin on the sides. I also ground all the casting sprues on the piston, and polished up the windows. Don't know if that will help, but it sure looks better. If this thing ever runs again, it'll be a miracle.

 

[woodworkingboy]

Widening the windows and beveling from inside to out on the edges, should improve gas flow and lighten up the piston. It's surprising how much you can take off those, and they still hold together. Don't go wider than you want to and leave an open port when it should be closed.

 

[squisher]

Windows = ports?

I'm slowly getting along in my projects. I got my little 024 donor up and running in stock form yesterday, real low compression 90pds. So I'm thinking I should do a piston and rings when doing it too?

My 046 that's getting rebuilt didn't have much better 110pds but it will be going back together with a new jug and cylinder. I want to practice on this 024 first though.

Would y'all recommend getting the 024 up and running/broke in with good compression before attempting any surgery?

Just serviced and cleaned up my main fleet too getting ready for the season.

 

[SkwerI]

On the 024, why not do both at the same time? Work the jug and use a new piston and rings when you slap it back together.

 

[squisher]

The only reason I was thinking not to would be so that I could see what gains, if any, I got out of the mod(which will be my first). But I'll probably just do it all at once so that I can get onto my 46.

 

[sotc]

youll know, youve got modded saws

 

[squisher]

I've never owned a saw this small though besides the 200t's. But yah I'll be able to finger it out I think.

 

[sotc]

if it cuts faster with a 20" bar than a 200t when your done, it better

 

[sotc]

check out my vids with the old saw and the hot saw and use that for comparison

 

[squisher]

Will be doing that for sure, when I get there. I'll go down and price out/order a piston and rings for it today. Depending on what my local sawshop wants I may have to mailorder it though.

And yes Willie it's still freezing in my shop.

 

[sotc]

put something over you boxers and get out there!

 

[squisher]

Nothing ordered yet, but I've stripped er down, now just gotta go re-read this thread.

 

[sotc]

so ez you wont ship it to me now

 

[squisher]

Willie were you able to work the ports at all from the inside of the cylinder? I don't have one of those flexible shafts, mine's rigid . Just wondering if it's worthwhile getting one or if you can't get inside with it anyways?





Seriously though.

 

[sotc]

i did very little from the inside as far as champfering the ports. for the second one i did, i bought cutting burs to move large volumes of material in the ports and used stones for the hardend sleeve work. i think its worth having the flexible shaft if your going to do your own saws but i think every thing i did could have been done without it

 

[T0RN4D0]

Hi, new here, and sorry for bringing up this old but excellent topic. Thanks to everyone posting the info, i went through it once but i'll have to go one more time slowly

I just got a used 026 and am thinking of opening it up a little bit. I've been reading a lot about porting saws lately and like to tinker with thing like that at home, so i want to try it. I'm no mechanic tho, so i would just like to get some things straight.

If i got everything i just pull off the top, remove the muffler, remove the cylinder, and just widen the intake a bit and the outlet a bit. I think side ports are hard to operate on and i probably wouldn't touch them much. I remove the gasket and check squish. If squish is OK reassemble with a liquid gasket, tune it and have fun cutting. :] Did i forget anything? Should I replace anything else while i have it opened? In case yamabond wouldn't be enough i should get a new seal i guess, do i need anything else? Can i mess it up? If its easy to mess up than i think i'll just open up the muffler a bit.

Sorry for all the questions, but better safe than sorry, right?