Are bars all the one width - Standard vs NK

[Fatherwheels]

I am thinking of putting a narrow kerf bar and chain on a saw I have coming,
it currently runs .325 by .058, if I put a .325 by .50 narrow kerf bar on that saw,
will I end up with a clutch cover that will be over tightened against the frame of
the saw in order to grab the bar, or are all bars the same width regardless
of being .043 .05 .058, they sure don't look the same with, so how does this work out,
have no narrow kerf bars around to try it and don't want to buy if its not workable.

 

[NSEric]

What saw do you have?
Chances are someone on here has one and tried nk on it.
The nk bars are a little thinner, that's the whole point of nk but 99/100 times they still fit fine.

 

[Fatherwheels]

What saw do you have?
Chances are someone on here has one and tried nk on it.
The nk bars are a little thinner, that's the whole point of nk but 99/100 times they still fit fine.

Are you sitting down, its an Efco MT 5200 / Oleo Mac 952

 

[Philbert]

Narrow kerf bars are thinner. They may still work. In the ‘worst case scenario’ you may need to make a spacer for the outboard side of the bar.

Philbert

 

[Fatherwheels]

Narrow kerf bars are thinner. They may still work. In the ‘worst case scenario’ you may need to make a spacer for the outboard side of the bar.

Philbert

I could do that @Philbert.
I also note you can buy a new 550XP with either NK or standard bars here,
so Husqvarna must have allowed for this, other wise the clutch cover would
push very tightly against the saw case in order to tighten down on a NK bar,
come to think of it, Stihl are now shipping the 261 with a NK bar and chain,
unless they are making two different clutch covers they must have allowed for
the 30 or 40 thou difference between the NK and Standard bars.

 

[Franny K]

In the 0.325 pitch and 0.050 gauge the Oregon NK bars are 1.550 to 1.555 and the ones for lpx bpx lgx are 1.570 to 1.575. Laminated bars sprocket nose. Not sure I always get the same measurement and have a few of the NK ones. The tie straps of the Oregon .325 seem to be made from 0.043 gauge stock and the tie straps for the lpx class stuff is more either 0.050 or perhaps more without re measuring. The 3690 Stihl 23rspro chain uses 0.050 stock for the tie straps and no necked down drive links, the Oregon Nk and H30 does have necked down drive links. I have not broken apart the new Husky .325nk think it has an 33 in the product code.

That is 20 thousands of an inch thickness difference. Anyone measure and come up with more? Sure the solid replaceable nose bars (and laminated bars with a thicker center lamina) are going to be more in some brands. Nk bars generally have 10 tooth noses, not sure what the Stihl choices are and if they differ from 3005 to 3003 mount.

 

[Fatherwheels]

In the 0.325 pitch and 0.050 gauge the Oregon NK bars are 1.550 to 1.555 and the ones for lpx bpx lgx are 1.570 to 1.575. Laminated bars sprocket nose. Not sure I always get the same measurement and have a few of the NK ones. The tie straps of the Oregon .325 seem to be made from 0.043 gauge stock and the tie straps for the lpx class stuff is more either 0.050 or perhaps more without re measuring. The 3690 Stihl 23rspro chain uses 0.050 stock for the tie straps and no necked down drive links, the Oregon Nk and H30 does have necked down drive links. I have not broken apart the new Husky .325nk think it has an 33 in the product code.

That is 20 thousands of an inch thickness difference. Anyone measure and come up with more? Sure the solid replaceable nose bars (and laminated bars with a thicker center lamina) are going to be more in some brands. Nk bars generally have 10 tooth noses, not sure what the Stihl choices are and if they differ from 3005 to 3003 mount.

Thanks @Franny K
I have at least four New SP33G Husqvarna NK .325 chains, this is why I
was looking into getting a NK bar, I will just have wait and see if there is
any wiggle room between the clutch cover to allow for a slightly narrower bar.
20 thou doesn't seem much, but it could cause oil to leak out as the bar studs
will only bend in the centre of the cover if the sides do not have clearance to
pull in flush that will not grip a bar correctly nor seal the oil in.

I looked and the Speed Cut Oregon bars have a good big nose on them,
while other NK Oregon bars have smaller diameter noses, they all list 64
drive links, so at least bars are available to suit my chains.

 

[Franny K]

I looked at my notes and the tie straps for the full size .325 measured in thickness. 0.052 for Oregon and 0.053 for the 23 rs and rm Stihl.

The speed cut laminated aluminum core with the NK symbol on them have 10 tooth noses while the versa cut ones that also have an aluminum core have a larger nose. I do have a 20" 78 dl speedcut one here, I have a woodland pro or the Baileys house brand universal mount in 18" 72dl and it counts 11 tooth nose even though it says 10 on their site, was a while ago I got it.

NK chain works fine on the standard .050 bars at least when new, It likely depends exactly what you are doing. The NK ones being narrower top to bottom will be lighter and less likely to cut as straight. I doubt weight matters a whole lot for 15" called length 64dl.

 

[Philbert]

That’s a lot of measuring!

I was thinking more like, if the bar wiggles, or if the oil leaks out, adding a couple pieces of aluminum duct tape to each side of the bar and cut out the necessary holes.

Whatever works.

Philbert

 

[Franny K]

One batch of measuring was comparing the splicing components. The other episode was figuring out how the various hard nose bars compared to the sprocket nose ones. The small Sugihars ones sometimes found on ebay are the thickness of the 3/8lp and .325NK. Similar for the Oregon laminated hard nose ones. Putting the bigger chain on the narrower bar would be more likely to dig into the powerhead or clutch cover. Some models have replaceable wear pieces.

 

[2lumbarleft]

Are you sitting down, its an Efco MT 5200 / Oleo Mac 952

I ran several Efco 152 chainsaws that were "basically" the same as the MT5200. I had no trouble running narrow kerf. Also, other than being well built like a tank, they were great saws. The only problem I saw on that model were the ignition switches failing, but that was no big deal to replace. Once modded and carb re-adjusted, they had plenty of grunt. I thought the build quality was impressive for the money.

 

[Fatherwheels]

I ran several Efco 152 chainsaws that were "basically" the same as the MT5200. I had no trouble running narrow kerf. Also, other than being well built like a tank, they were great saws. The only problem I saw on that model were the ignition switches failing, but that was no big deal to replace. Once modded and carb re-adjusted, they had plenty of grunt. I thought the build quality was impressive for the money.

Thank you @2lumbarleft , I am happy to hear your experience with the 152 / MT5200 was a positive one.
I ordered one cheap at a sale, should arrive in a few days. I fully intend to gut the muffler, and re tune.
I have already eyed up a replacement ignition switch from a scrap saw I have here, so no worries, replacements
are still available here too, as is every part except the clutch cover.

When you say re jet, did you put different jets in the carb, maybe you could explain more about this,
I do not intend to do any port work, though a gasket delete may happen if there is a positive gain
in available power.

I want this to be my light saw, and so the idea of going to NK bar and chain, but with 50cc on tap,
maybe I should leave well enough alone.

 

[2lumbarleft]

Thank you @2lumbarleft , I am happy to hear your experience with the 152 / MT5200 was a positive one.
I ordered one cheap at a sale, should arrive in a few days. I fully intend to gut the muffler, and re tune.
I have already eyed up a replacement ignition switch from a scrap saw I have here, so no worries, replacements
are still available here too, as is every part except the clutch cover.

When you say re jet, did you put different jets in the carb, maybe you could explain more about this,
I do not intend to do any port work, though a gasket delete may happen if there is a positive gain
in available power.

I want this to be my light saw, and so the idea of going to NK bar and chain, but with 50cc on tap,
maybe I should leave well enough alone.

Thank you @2lumbarleft , I am happy to hear your experience with the 152 / MT5200 was a positive one.
I ordered one cheap at a sale, should arrive in a few days. I fully intend to gut the muffler, and re tune.
I have already eyed up a replacement ignition switch from a scrap saw I have here, so no worries, replacements
are still available here too, as is every part except the clutch cover.

When you say re jet, did you put different jets in the carb, maybe you could explain more about this,
I do not intend to do any port work, though a gasket delete may happen if there is a positive gain
in available power.

I want this to be my light saw, and so the idea of going to NK bar and chain, but with 50cc on tap,
maybe I should leave well enough alone.

Perhaps you have mistakenly confused my reply content with that of another responder, but I never said that I re-jetted the carb. I merely re-adjusted the 152 to a richer flow to accommodate the reduction in back pressure. Because I have never personally worked on an MT5200, if they have non-adjustable fixed jet carburetors, then yes you would have to find a way to re-jet or replace the existing carburetor with an adjustable carburetor. If the Carburetor is non-adjustable and you leave it as is, do not attempt to reduce back pressure on the saw, as you will go lean and score your cyclinder. However, I am guessing that your carburetor IS adjustable, but has limiters in place. I have worked on so many different saws that I don't remember the specifics on each modification, but I recently worked on an MT4400 (out of production), and it had limiters that removed just like on ECHO chainsaws. While the MT4400 is a less expensive saw without a magnesium crankcase, it still has excellent features like a fully adjustable oiler, decompression valve and side tensioning chain adjuster. They have excellent air filters and wonderful balance with a 16" narrow kerf bar. Total empty weight with 16" bar and chain installed was 12.44 pounds. That is not bad for a 42.9 cc saw with dual piston rings and high compression. I never turn my nose up at any saw unless I have actually tried it. When I had less experience, I first thought the old Redmax brand was a cheap saw more like newer Poulans until I worked with them. I bought a G5000 and that thing cranked like the 346XP. Of course, then they got bought out.

 

[northmanlogging]

I am thinking of putting a narrow kerf bar and chain on a saw I have coming,
it currently runs .325 by .058, if I put a .325 by .50 narrow kerf bar on that saw,
will I end up with a clutch cover that will be over tightened against the frame of
the saw in order to grab the bar, or are all bars the same width regardless
of being .043 .05 .058, they sure don't look the same with, so how does this work out,
have no narrow kerf bars around to try it and don't want to buy if its not workable.

to be clear, your concern here is whether the bar will fit the saw? not so much as to whether they are different thicknesses, cause they are.

shouldn't be a problem with the bar fitting any saw with the correct bolt oil hole arrangement, the thickness differences are minimal, like less then a full revolution of the retaining nuts.

 

[Fatherwheels]

Perhaps you have mistakenly confused my reply content with that of another responder, but I never said that I re-jetted the carb. I merely re-adjusted the 152 to a richer flow to accommodate the reduction in back pressure. Because I have never personally worked on an MT5200, if they have non-adjustable fixed jet carburetors, then yes you would have to find a way to re-jet or replace the existing carburetor with an adjustable carburetor. If the Carburetor is non-adjustable and you leave it as is, do not attempt to reduce back pressure on the saw, as you will go lean and score your cyclinder. However, I am guessing that your carburetor IS adjustable, but has limiters in place. I have worked on so many different saws that I don't remember the specifics on each modification, but I recently worked on an MT4400 (out of production), and it had limiters that removed just like on ECHO chainsaws. While the MT4400 is a less expensive saw without a magnesium crankcase, it still has excellent features like a fully adjustable oiler, decompression valve and side tensioning chain adjuster. They have excellent air filters and wonderful balance with a 16" narrow kerf bar. Total empty weight with 16" bar and chain installed was 12.44 pounds. That is not bad for a 42.9 cc saw with dual piston rings and high compression. I never turn my nose up at any saw unless I have actually tried it. When I had less experience, I first thought the old Redmax brand was a cheap saw more like newer Poulans until I worked with them. I bought a G5000 and that thing cranked like the 346XP. Of course, then they got bought out.

Yes, I read that wrong, glad to hear no re jetting is required. I sure hope the carb has adjustable screws,
if it doesn't then I will be keeping a close eye to what happens when I gut the muffler, I can not stand cats.
New mufflers are not easy to get to put a 152 can on the Efco, so I suspect some butchering will ensue.

 

[Fatherwheels]

to be clear, your concern here is whether the bar will fit the saw? not so much as to whether they are different thicknesses, cause they are.

shouldn't be a problem with the bar fitting any saw with the correct bolt oil hole arrangement, the thickness differences are minimal, like less then a full revolution of the retaining nuts.

Well I don't know exactly what mount is on the MT5200, other than what I read which indicates its a K095, I can get K095
bars that are narrow kerf, the Husky X-Cut bars come in 15 inch / 64 link and wear the Husky SP33G chain I have in stock,
the width is what worried me, but from what I hear now, its not a lot, and there are ways to work around it.

 

[Fatherwheels]

Well the Efco arrived in the post today.
Not going to put the NK setup on this saw,
the power head is heavy, and I think it will result
in a very skittish saw, like trying to write with a 2lb
top heavy pencil.

I will sell it on if I can, and get a lighter saw for what I want,
if no one bites then I will keep it and use it alongside my yet
to be light saw purchase.

It didn't come too lean from the factory either, and no anti tamper
restrictions visible, not sure if that's a cat muffler, I sure hope not.

It has a K095 mount, which means the Carlton 01W mount bar I have
will fit right on there, its 15 inch so will reduce the weight a little.

 

[Fatherwheels]

Its an odd saw, The ID tag says its a GS520, yet the side plate
says MT5200, I know they are both the same item, still find that odd.

 

[Philbert]

Not going to put the NK setup on this saw,
the power head is heavy, and I think it will result
in a very skittish saw

Because they are thinner, narrow kerf bars tend to be more flexible, which some guys don’t like. The Oregon Speedcut bar a a NK bar that is a little stiffer, due to its laminated construction.

Philbert

https://www.arboristsite.com/thread...f-chain-and-speedcut-guide-bars.285694/page-8