MS390 / 039 pop up piston

[Jon1212]

VB, VA is a far Piece.

What’s the Skinny?

Still....er.....Stihl no word.....interviewed on 11/28 and 11/29, told on 12/05 that I would here something on 12/08.....*cricket* *cricket*

 

[hseII]

Is it wrong to put a blown up 029 on my Christmas wish list to Santa Clause?

I assumed that’s what you asked him for last week when y’all went to see him.

 

[Northwet]

http://baileysonline.com/Chainsaw-B...tihl-Chainsaws.axd?PartFinderType=BarSelector

Baileys has a 20 inch narrow kerf 325 bar.

 

[hseII]

http://baileysonline.com/Chainsaw-B...tihl-Chainsaws.axd?PartFinderType=BarSelector

Baileys has a 20 inch narrow kerf 325 bar.

What is the size difference between NK & regular .325”?

 

[RI Chevy]

You know he’s fackin with you right?

I do. But if someone wants to build a saw, then so be it.

 

[Terry Syd]

On NK .325 the cutters are 1mm thick, while a standard .325 chain the cutters are 1.25mm thick. That's what makes the kerf more narrow by .5mm (.25mm on each side).

IMO the main reason NK cuts so much faster, it is because the cutter is thinner and has less resistance to entering the wood. Think of the difference between a thin wood chisel and a thick wood chisel. The thinner one will enter and go deeper for the same amount of pressure.

You can also use more cutting angle (raker depth) to move more wood for the same amount of resistance.

EDIT: Now that this saw has been set up to use the K095 bar, if I wear this one out I'll switch to the newest NK bar. Philbert did an analysis on it and it was lighter and more rigid than the one I'm running.

Cool that Woodland Pro offers a NK for Stihls. Their recent NK chain (Carlton) is now my preferred chain. It has a tighter bend and is very close to full chisel. It is also tough, the metallurgy feels like a Stihl chain when you file it.

 

[Adirondackstihl]

I assumed that’s what you asked him for last week when y’all went to see him.

I haven’t been back to the Norf Pole in a few days

 

[hseII]

I haven’t been back to the Norf Pole in a few days

 

[Adirondackstihl]

 

[Terry Syd]

I just got my pop-up in the mail. Beautiful casting and machine work. It will be the prettiest thing on this old POS. Thankfully it will be inside where nobody can see it. I wouldn't want to alter the overall crappy look to this 'sleeper' that I've worked so hard to achieve.

 

[94BULLITT]

I just got my pop-up in the mail. Beautiful casting and machine work. It will be the prettiest thing on this old POS. Thankfully it will be inside where nobody can see it. I wouldn't want to alter the overall crappy look to this 'sleeper' that I've worked so hard to achieve.

Mines pretty rough looking too. It is half 029 and half MS 290 on the exterior. Do you have a scale to weigh your piston?

 

[94BULLITT]

On NK .325 the cutters are 1mm thick, while a standard .325 chain the cutters are 1.25mm thick. That's what makes the kerf more narrow by .5mm (.25mm on each side).

IMO the main reason NK cuts so much faster, it is because the cutter is thinner and has less resistance to entering the wood. Think of the difference between a thin wood chisel and a thick wood chisel. The thinner one will enter and go deeper for the same amount of pressure.

You can also use more cutting angle (raker depth) to move more wood for the same amount of resistance.

EDIT: Now that this saw has been set up to use the K095 bar, if I wear this one out I'll switch to the newest NK bar. Philbert did an analysis on it and it was lighter and more rigid than the one I'm running.

Cool that Woodland Pro offers a NK for Stihls. Their recent NK chain (Carlton) is now my preferred chain. It has a tighter bend and is very close to full chisel. It is also tough, the metallurgy feels like a Stihl chain when you file it.

Do you run a 8 or 9 tooth sprocket? Did you try the NK against 3/8?

 

[Terry Syd]

Mines pretty rough looking too.

I bet mine is uglier than yours. I spent some time looking for the ugliest bar cover I could find so I could cover up the NK bar. The shop owner brought it out and I immediately wanted it (freaking ugly, never seen anything like it), he put it on the counter and said "its yours, I just want to get rid of it" (I would have given him $20 for it).

I've run NK on my 50cc saw next to a few 60cc saws running 3/8 and the 50cc was always faster. However, I mod my saws and know how to sharpen a chain. I ran the 3/8 on this 029 when I first got it running. It cut well, but was heavy. The NK is faster cutting and makes it a great handling saw. I run an 8-pin. If you are cutting softwood, you might want to try a 9-pin.

EDIT: I don't have a scale, but I'll do a before and after compression test. The actual numbers may not be all that relevant, but the percentage of change will be.

 

[94BULLITT]

I bet mine is uglier than yours. I spent some time looking for the ugliest bar cover I could find so I could cover up the NK bar. The shop owner brought it out and I immediately wanted it (freaking ugly, never seen anything like it), he put it on the counter and said "its yours, I just want to get rid of it" (I would have given him $20 for it).

I've run NK on my 50cc saw next to a few 60cc saws running 3/8 and the 50cc was always faster. However, I mod my saws and know how to sharpen a chain. I ran the 3/8 on this 029 when I first got it running. It cut well, but was heavy. The NK is faster cutting and makes it a great handling saw. I run an 8-pin. If you are cutting softwood, you might want to try a 9-pin.

EDIT: I don't have a scale, but I'll do a before and after compression test. The actual numbers may not be all that relevant, but the percentage of change will be.

I have a 290/390 running a .325 9 pin. It has a nylon mesh filter and little clean up on the cylinder. I have not modded the muffler on it yet. It runs the 9 pretty good for bucking. I think it will handle it very well after I mod the muffler.

I'm hoping my saw with the pop up will be healthier and I think it will.

The NK 325 has always interested me. I've always wondered how it would perform on a 60cc since 3/8lp is so good on 50cc. The bad thing about NK is I would have to order it, it is not available local.

Sent from my SM-G950U using Tapatalk

 

[beaglebriar]

I've got a Huztl jug. I'll put some clay on the piston and check the clearance, but I expect it will be alright (hopefully it will be TOO tight and I have to trim a bit). The Huztl jug has a central combustion chamber.

Did you have a chance to check this Terry? I have a ms310 here that's been straight gassed.

It's gonna get the 390 treatment, just have to settle on what cylinder to use.

 

[94BULLITT]

The Cross 390 cylinder is really nice.

Sent from my SM-G950U using Tapatalk

 

[beaglebriar]

The Cross 390 cylinder is really nice.

Sent from my SM-G950U using Tapatalk

I might go that route or the Hyway. It's a budget build for a friend and the Hyway is a bit cheaper.

 

[Northwet]

I put the Huztl cylinder on mine with the cross piston and everything clears. Squish was not great. The pistons measured damn near the same pin to crown.

 

[beaglebriar]

I put the Huztl cylinder on mine with the cross piston and everything clears. Squish was not great. The pistons measured damn near the same pin to crown.

Any idea what the squish was?

 

[Northwet]

I just measred, it' about .045