# 3/8 lp vs. 3/8



## Motodeficient (Jun 19, 2009)

What exactly is the difference between 3/8 LP and 3/8? A saw running 3/8LP can run regular 3/8 as long as it has a regular 3/8 bar? Is the 3/8 that much more aggressive than 3/8 LP?

I am going to ditch the junky stock bar and chain on this Ryobi 10532, but I don't know if it will run 3/8 well or if I should stick with 3/8LP. I am going to muffler mod it tonight for a little more power, but its still going to be a 40cc saw.


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## striperswaper (Jun 19, 2009)

go with the lp, check the threads for this saw and Bailey's has a good deal on bar/chain combos


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## Mad Professor (Jun 19, 2009)

You need a 3/8 clutch sprocket and the same for the bar if sprocket tipped; you can't just switch chains.


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## blsnelling (Jun 19, 2009)

That little Ryobi could never pull regular 3/8 chain. It's MUCH larger and cuts a MUCH wider kurf.


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## computeruser (Jun 19, 2009)

blsnelling said:


> That little Ryobi could never pull regular 3/8 chain. It's MUCH larger and cuts a MUCH wider kurf.



+1.


It would be interesting to know how would it do with .325, though...


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## blsnelling (Jun 19, 2009)

computeruser said:


> +1.
> 
> 
> It would be interesting to know how would it do with .325, though...



It may do great with .325 chisel chain. I know the Dolmar 420 does, but that's more saw yet.


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## SilverBox (Jun 19, 2009)

Around 4hp (50+ cc) you need to switch to regular 3/8 instead of LP. Until then LP will generally cut faster. Some guys will run LP on larger milling saws (because of the narrower kerf) but unless your very gentle, you snap chains, LP just isn't strong enuf for big saws.


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## HimWill (Jun 19, 2009)

Stick with the LP,just too easy not to.After a muffler mod it will pull it with authority.The 6 tooth sprocket helps here,if it had a little more "juice" you might be tempted to go to a 7.I have no idea where you could get a 7 tooth for it though.


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## Snapperhead (Jun 19, 2009)

Please answer the question that the OP asked, because I wanna know too. Can the bar and sprocket that drives 3/8LP also drive 3/8 or not? Is the profile of the drivers the same? I realize the gauge has to be the same. 

And why cant a 40cc saw pull 3/8 chain? Seems like all the oldtime saws din't have LP chain, so whats the beef, juss the speed of the saw?


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## HimWill (Jun 19, 2009)

For what it's worth, standard 3/8 is listed as .375 pitch.The 3/8 LP is listed as .365 pitch,some 1/100th of an inch difference there.Who knows how significant this is, on a worn 3/8 LP sprocket probably OK to try standard 3/ 8.


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## super3 (Jun 19, 2009)

Snapperhead said:


> Please answer the question that the OP asked, because I wanna know too. Can the bar and sprocket that drives 3/8LP also drive 3/8 or not? Is the profile of the drivers the same? I realize the gauge has to be the same.
> 
> And why cant a 40cc saw pull 3/8 chain? Seems like all the oldtime saws din't have LP chain, so whats the beef, juss the speed of the saw?



See post no. 3


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## computeruser (Jun 19, 2009)

Snapperhead said:


> And why cant a 40cc saw pull 3/8 chain? Seems like all the oldtime saws din't have LP chain, so whats the beef, juss the speed of the saw?



It can, but not as well as it can pull .325" or 3/8LP. I suppose you could mitigate that somewhat by running your rakers tall (.015, .020), so the saw would stay up in its powerband.

The oldtimers were turning a lot lower RPMs than modern saws, had more torque (torque rise?) than the modern saws, and these attributes make a chain that takes relatively larger bites an appropriate choice.

This little guy is running .325" and cut like a madman, but could easily have pulled 16" of 3/8".


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## deezlfan (Jun 19, 2009)

> Originally Posted by Snapperhead
> Please answer the question that the OP asked, because I wanna know too. Can the bar and sprocket that drives 3/8LP also drive 3/8 or not? Is the profile of the drivers the same? I realize the gauge has to be the same.
> 
> And why cant a 40cc saw pull 3/8 chain? Seems like all the oldtime saws din't have LP chain, so whats the beef, juss the speed of the saw?
> ...





> You need a 3/8 clutch sprocket and the same for the bar if sprocket tipped; you can't just switch chains.



Soooo, 3/8' LoPro isn't really 3/8". You didn't explain why 3/8 LP chain isn't 3/8th chain. I knew my old Homelite had two different spurs, but couldn't figure why. The bar will run either however. What's up with that? 

Not to criticize anyone, but just saying you can't do it doesn't help the newbies. I see a lot of people jumping in on some subjects, dragging the thread off tangent and the basic question never gets answered. I have worked around *** for many years, but some subjects are just beyond my reach. Please try to remember that a lot of people here don't have 1000 muffler mods under their belts. Thanks.


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## super3 (Jun 19, 2009)

deezlfan said:


> Soooo, 3/8' LoPro isn't really 3/8". You didn't explain why 3/8 LP chain isn't 3/8th chain. I knew my old Homelite had two different spurs, but couldn't figure why. The bar will run either however. What's up with that?
> 
> Not to criticize anyone, but just saying you can't do it doesn't help the newbies. I see a lot of people jumping in on some subjects, dragging the thread off tangent and the basic question never gets answered. I have worked around *** for many years, but some subjects are just beyond my reach. Please try to remember that a lot of people here don't have 1000 muffler mods under their belts. Thanks.




I thought post no. 10 answered what the exact difference was,and as far as people derailing the thread,,,well, get used to it,it won't change anytime soon. Besides if all we done was answer the questions with no other interjection it would get pretty boring.
Besides you're a newbie, so am I,pay your dues.


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## Mad Professor (Jun 19, 2009)

deezlfan said:


> Soooo, 3/8' LoPro isn't really 3/8". You didn't explain why 3/8 LP chain isn't 3/8th chain. I knew my old Homelite had two different spurs, but couldn't figure why. The bar will run either however. What's up with that?
> 
> Not to criticize anyone, but just saying you can't do it doesn't help the newbies. I see a lot of people jumping in on some subjects, dragging the thread off tangent and the basic question never gets answered. I have worked around *** for many years, but some subjects are just beyond my reach. Please try to remember that a lot of people here don't have 1000 muffler mods under their belts. Thanks.



If the bar tip sprocket is worn to crap it might work with both chains. 

The threads above have explained things, get some calipers out and prove it to yourself.


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## nmurph (Jun 19, 2009)

i think all 3/8" is .365. it is a misnomer that it is called .375.


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## HimWill (Jun 20, 2009)

Here are a couple of links to Bailey's chains, regarding pitch read additional specs:

3/8 LP
http://www.baileysonline.com/itemdetail.asp?item=WP365+30LP&catID=830

3/8 reg.
http://www.baileysonline.com/itemdetail.asp?item=WP375+30SC&catID=831

I wasn't making it up,just reporting the facts.Why they are different,who knows.


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## MCW (Jun 20, 2009)

Massive difference between the two and they are not interchangeable.
I have heard someone say that you can run 3/8"LP on a standard 3/8" rim sprocket - just checked and it does look like it would work.
Standard 3/8" a lot larger in all respects than 3/8"LP.






3/8"LP will not work on a standard 3/8" bar sprocket...






and standard 3/8" will not work on a 3/8"LP bar sprocket...






Hope this clears it up. Low Profile bar nose sprockets have obviously rounded teeth, standard 3/8" does not.


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## KiwiTony (Jun 20, 2009)

Thanks for the pictorial MCW. I'm sure that the photos will explain the difference far better than a hundred words ever will.


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## MCW (Jun 20, 2009)

KiwiTony said:


> Thanks for the pictorial MCW. I'm sure that the photos will explain the difference far better than a hundred words ever will.



No worries mate. Pictures make the difference painfully obvious


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## BobL (Jun 20, 2009)

I run 050 3/8 LP on my all plastic homelite, I use a standard 3/8 drive sprocket on a hardnose 20", seems to work pretty well. Am thinking of getting a couple of loops to run on the 441 , now I gotta get me a bar.


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## nmurph (Jun 20, 2009)

HimWill said:


> Here are a couple of links to Bailey's chains, regarding pitch read additional specs:
> 
> 3/8 LP
> http://www.baileysonline.com/itemdetail.asp?item=WP365+30LP&catID=830
> ...




here is something to the contrary from Bailey's:



> http://www.baileysonline.com/itemdetail.asp?item=OR375+91VX&catID=797


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## Mad Professor (Jun 20, 2009)

BobL said:


> I run 050 3/8 LP on my all plastic homelite, I use a standard 3/8 drive sprocket on a hardnose 20", seems to work pretty well. Am thinking of getting a couple of loops to run on the 441 , now I gotta get me a bar.




Let us know how the drive sprocket looks after a few tanks of fuel.


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## BobL (Jun 20, 2009)

Mad Professor said:


> Let us know how the drive sprocket looks after a few tanks of fuel.



Well, I reckon I have milled about 15 (small) logs with the plastic homelite 340 over a period of about 2 years with that combo and the drive sprocket's got about the amount of wear I'd expect for that much cutting. One difference is that the Homelite does have a spur and not a rim sprocket although I can see that would make any difference, or maybe it does?


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## deezlfan (Jun 20, 2009)

Well fair enough, a picture is worth a thousand words. But riddle me this gentleman........ 

This is a 16" Tilton SuperBar that has seen service on my Homelite 240 since about 1987 [1]. Always ran the original size 3/8" chain [2]. A couple of years ago I needed a new spur and the only one in stock at my local chainsaw guy was for LP. Swapped the spur and installed a loop of LP chain and haven't looked back [3]. 


















And just so you can't say I am using photographic trickery, here's the two chains side by side. 






And to counter the previous supposition, the bar nose and sprocket are not 'worn to crap'.  
They are in excellant shape for the age and usage this saw has received.


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## deezlfan (Jun 20, 2009)

Additional point. If you look closely at the fourth photo you will see the top chain's links are marked 91 which is Oregon 3/8" LP chain and the lower is marked 72 which is their regular 3/8".


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## striperswaper (Jun 20, 2009)

so measure the distance between 3 rivets and divide by 2 on both chains
whatdaya get .325, .365, .375, .404?


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## Noko (Jun 20, 2009)

*3/8LP Chain on 3/8 Rim*

Hi,

I run 3/8LP Chain on Regular 3/8 Rim Sprocket, but Bar (Sprocket Nose) is for 3/8LP.

So far this setting has been working fine for me.

Noko


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## BobL (Jun 20, 2009)

deezlfan said:


> Well fair enough, a picture is worth a thousand words. But riddle me this gentleman........
> .
> .
> .
> ...



Good Post DZL! 

On the drive sprocket side I agree, at the other end I cannot say because I use a hardnose.

As an aside, you must be cutting soft wood because the length of some of the 3/8 cutters would snap off in some of the wood I cut. Also it looks like you have an alternating filing issue with the outside cutter being longer than the inner cutters, or is it a photographic thang?


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## deezlfan (Jun 20, 2009)

BobL,

Both those chains were in my junk pile, grabbed out for photographic purposes only. The original 3/8" chains from my 240 moved on to other saws when I changed it to LoPro. I wanted to illustrate that at least a few bars will accept both types of chain without issues. Obviously there would be geometry conflicts when the depth of the bar and diameter of the sprocket changes. As the earlier photos clearly illustrate, in most cases they are not interchangable. But because this bar did accept them both, it cause me to wonder until I learned the differences. 

You are correct there are issues with the sharpening techniques employed on that particular chain. In fact a chain just like that starred in one of my threads a couple of weeks ago regarding how far you could/should use a chain. The general consensis was use it until the teeth come off, then use it some more. I personally wouldn't risk it. You should see some of the chains that come through the door of my shop since I started buying saws for parts! I can't take credit for the maintainance of either of those chains.


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## MCW (Jun 20, 2009)

deezlfan said:


>



The rounded off teeth on the sprocket nose looks like that bar was originally meant for 3/8"LP anyway? Maybe bars have changed since the '80s 
You most certainly can't put 3/8"LP chain on any of the sprocket nose bars I have in stock that are meant for standard 3/8".


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## deezlfan (Jun 20, 2009)

That may be the case but this bar is not marked for any particular chain size. I purchased it a pro shop after a buddy dropped a tree on the original Homelite laminated bar not long after I got the saw. I shutter to think that the saw shop sold me the wrong bar all those years ago. But with almost 20 seasons, I never had an issue with the chains jumping off or damage to either the bar or chain.


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## MCW (Jun 20, 2009)

deezlfan said:


> That may be the case but this bar is not marked for any particular chain size. I purchased it a pro shop after a buddy dropped a tree on the original Homelite laminated bar not long after I got the saw. I shutter to think that the saw shop sold me the wrong bar all those years ago. But with almost 20 seasons, I never had an issue with the chains jumping off or damage to either the bar or chain.



It does look like your chains fit that bar pretty well though regardless.


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## deezlfan (Jun 20, 2009)

I guess the next question would be: WHY couldn't they have made 3/8LP so that the drive links and and pitch were the same? Seems like it would have been easier all around. Perhaps it would space the raker too far from the tooth?


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## heimannm (Jun 20, 2009)

I think the pitch is in fact the same and is really .365, they just call it 3/8" or .375 for convenience.

The drive links are different, and the LP chain is narrower to remove less material making it easier for an underpowered saw to cut, like a thin kerf blade for your table saw or portable circular saw. The LP chain is also quite a bit lighter, thinner material that is not as strong since it won't be exposed to high HP.

Mark


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## nmurph (Jun 20, 2009)

thank you Mark for that confirmation.


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## Okie (May 16, 2017)

Another question about LP vs standard chains for a EZ chainsaw.

I see the difference in the pictures of the roller tip bars for the LP and standard, the LP bars have the round teeth.
I think my Homelite 16 inch OEM bars are for the standard chains. (I'll take a look to confirm)

I have couple of EZ's that have the solid bar, non roller tip bar, one has a 3/8 toothed sprocket and one has a rim sprocket.
*Can a LP chain be used on the solid type bar with the standard sprocket without damaging the sprockets*?

AND

It appears that the link is not as deep on the LP chain.* Will a standard bar have any problems with the LP links not cleaning the bottom of the groove ??? (oily fine dust building up in the bottom of the standard bar groove and possibly clogging the oiler hole also when using the lower Height LP chain?)

Got my questions answered. Just did not do enough reading.*


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## old guy (May 16, 2017)

I too used to claim you could use lp chain on regular 3/8 sprocket & bar & it does work sorta, but the sprockets are not the same & will run rough & wear fast.
I took an 026 Stihl on trade, it had a new full size 3/8 bar & chain on it but the chain ran very rough. I messed around with this for quite a while, the bar was plainly marked 3/8, the chain was obviously full size 3/8, the sprocket rim said 3/8p,
the (p) is the clue here, it is Stihl"s mark for picco their name for lo pro chain.
I went up to the saw shop and asked to see a standard 3/8 rim for that saw, there is a very small difference in cercumference, but the big difference is in the dividers between the drive links, they are much thicker in the lo pro rim.


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## Pioneer (May 16, 2017)

I just went through this myself a couple of months ago, tried to match l.p. vs regular 3/8 chains on the different type of rim sprockets. Didn't work. 
The base of the chain is farther away from the pins on the regular 3/8, meaning that when the chain is bent around an arc, the base describes a smaller circle than it would with a chain that has pins closer to the base, I.E. low profile. This is why the larger diameter .404 sprocket is actually a closer fit on the LP chain.
The local Stihl dealer confirms it, he sells different sprockets for 3/8 and l.p. 3/8, you put the two side by side and there is a noticeable difference .
Stick with the 3/8 l.p. bar/sprocket, and use the Stihl PS chain. Big difference in cutting speed. This little Husky 32 pulls it, your saw should as well.


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## Little Al (May 16, 2017)

computeruser said:


> +1.
> 
> 
> It would be interesting to know how would it do with .325, though...


It performs OK ( It's a saw I look after for a friend of a friend ) but I would not consider having to spend for Sprocket Chain & Bar as it's a non replaceable tip as against a new 3/8LP chain as to me the tiny gain ('if there was one) is not worth the extra expense. He took it in to a dealer for a chain to be told it needed the full set up replacing& he got it back 325 equipped didn't realize till he went to sharpen his chain & his husky roller guide woudn't fit


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## hseII (May 16, 2017)

I tried the Picco on my 50cc saws, but have went back to .325". 

Don't shoot me, but I started using a 3/8" file on .325", & honestly, it's nice. 

Of Course, my 50cc saws have stickers, so maybe that's the difference. 


YMMV

Holy Dead Thread Revival.


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## svk (May 16, 2017)

I have lots of saws that run lo pro or standard 3/8 and now am up to 2 saws that run .325. Since they are "sisters" in the same family of saw (350 Husky family) I am going to get one 3/8 sprocket for them and video a few cuts to see what the actual difference is. Would be nice to have one less set of chains and bars to worry about.


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## hseII (May 16, 2017)

svk said:


> I have lots of saws that run lo pro or standard 3/8 and now am up to 2 saws that run .325. Since they are "sisters" in the same family of saw (350 Husky family) I am going to get one 3/8 sprocket for them and video a few cuts to see what the actual difference is. Would be nice to have one less set of chains and bars to worry about.



I'm going to have 3/8 Picco regardless, because both my top handles & my Pole Saws run 3/8" 0.050" Picco.

I'm going to have 3/8" 0.063" because, well, that's the right chain for the medium saws.

I'm going to have .404", because I tried, (unsuccessfully I might add), to buy Julian out, & plus, that's what goes on Big Saws.

I think you'll see the .325" is the better chain for the 50cc saws.

I spent a fair amount of money to prove that to my hardheaded self.

I'm still going to use a 3/8" file on the .325", however.


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## svk (May 16, 2017)

I definitely hear what you are saying. In reality, .325 may be optimum for a 50 cc saw but for me it is a hassle to have one (or two) saws that run .325 when basically everything else I own can either share a 52 DL loop of 3/8 LP or a 60 or 72 DL loop of true 3/8. Since they do not make a 3/8 LP spur or rim for 350 Husky family, my choices are either go up to 3/8 or be "stuck" with .325. If they did have a LP option for those saws I would drop them down to Stihl PS chain and call it a day.

I will admit that .325 cuts smoother than 3/8 especially when limbing.


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## svk (May 16, 2017)

On another tangent. We know that a Homelite Super EZ which is somewhere in the neighborhood of 2.5-2.75 HP can pull a 16" loop of full 3/8. So if we use that as the baseline of what saws could "move up" than there are a number of saws on the market that certainly could as well. OTOH there are saws like the Poulan 5020 that IMO are way underpowered to come out of the box with a 20" loop of full 3/8.


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## old guy (May 16, 2017)

I have full 3/8 on my ported 346 and the one that will be ported, all my other 50s wear .325 except the 5020. I tried to move that to .325 but the clutch drum I bought would expand under the pressure of the clutch shoes and bind on the brake band.


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## Okie (May 17, 2017)

hseII said:


> I'm going to have 3/8 Picco regardless, because both my top handles & my Pole Saws run 3/8" 0.050" Picco.
> 
> I'm going to have 3/8" 0.063" because, well, that's the right chain for the medium saws.
> 
> ...


*

??*
*3/8" file *
*Are you referring to a 13/64 and/or a 7/32 inch file???*


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## hseII (May 17, 2017)

Okie said:


> *
> 
> ??*
> *3/8" file *
> *Are you referring to a 13/64 and/or a 7/32 inch file???*



The correct file for 3/8" chain.


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## a. palmer jr. (May 17, 2017)

Snapperhead said:


> Please answer the question that the OP asked, because I wanna know too. Can the bar and sprocket that drives 3/8LP also drive 3/8 or not? Is the profile of the drivers the same? I realize the gauge has to be the same.
> 
> And why cant a 40cc saw pull 3/8 chain? Seems like all the oldtime saws din't have LP chain, so whats the beef, juss the speed of the saw?


 The old Homelite Super EZ and 150 used regular 3/8 chain but saws back then had more grunt and less rpm.


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## a. palmer jr. (May 17, 2017)

You might just consider that 3/8 and 3/8LP are two different chains. The only thing they have in common is the distance between the pins. If you don't think your saw has enough chain with the LP then just convert it all to .325. I tend to go the other way with chains..my MS250 had a .325 chain on it and I went to 3/8LP and I'm glad I did. Length of bar also comes into play with this...


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## SAWMIKAZE (May 17, 2017)

What are guys using on the piltz hotsaw conversions for huskys ?

With some of the stihls with the mini spline you can run the P7 rim but for the standard and small spline husky saws what rim are they using to drive that PS chain ?


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## svk (May 17, 2017)

SAWMIKAZE said:


> What are guys using on the piltz hotsaw conversions for huskys ?
> 
> With some of the stihls with the mini spline you can run the P7 rim but for the standard and small spline husky saws what rim are they using to drive that PS chain ?


Not sure what you are saying here. Does Piltz make a 3/8 LP sprocket for the 350 family?


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## a. palmer jr. (May 17, 2017)

Piltz would more likely put a 28" bar and chain on a MS180 and call it a hot saw...


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## hseII (May 17, 2017)

svk said:


> I definitely hear what you are saying. In reality, .325 may be optimum for a 50 cc saw but for me it is a hassle to have one (or two) saws that run .325 when basically everything else I own can either share a 52 DL loop of 3/8 LP or a 60 or 72 DL loop of true 3/8. Since they do not make a 3/8 LP spur or rim for 350 Husky family, my choices are either go up to 3/8 or be "stuck" with .325. If they did have a LP option for those saws I would drop them down to Stihl PS chain and call it a day.
> 
> I will admit that .325 cuts smoother than 3/8 especially when limbing.



I had bad luck throwing 3/8lp on the 20" bar that was on my MS261.

YMMV


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## a. palmer jr. (May 17, 2017)

My 353 and 346 both run 18" bars and .325 chain, doubt if I'd try to use either 3/8 sizes on them. I could possibly go to a 20" bar but doubt if I will. I've had a few 350s also and they seemed happy with a .325 and 18" bar.


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## SAWMIKAZE (May 17, 2017)

svk said:


> Not sure what you are saying here. Does Piltz make a 3/8 LP sprocket for the 350 family?



What rim do they use to drive PS chain on a small and standard spline...mini spline is the only size i know of that has a designated rim for 3/8 lo-pro chain.


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## svk (May 17, 2017)

SAWMIKAZE said:


> What rim do they use to drive PS chain on a small and standard spline...


Not sure. I figured out that the small stihl and small husky rims should interchange. So I ordered a 3/8LP sprocket from Ebay to try it out. I have a bar that I can use and just need to pick up a 56DL loop of LP. Will be interesting to see.


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## old guy (May 17, 2017)

I don't believe small Stihl, small Husky interchange.


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## SAWMIKAZE (May 17, 2017)

old guy said:


> I don't believe small Stihl, small Husky interchange.



They dont.


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## svk (May 17, 2017)

Oregon has the same rim PN for 550 and 261...?


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## old guy (May 17, 2017)

If you have an oregon drum on the 261, if you the stihl drum, oregon won't fit it.


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## svk (May 17, 2017)

That makes sense


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## ladnar (Nov 22, 2021)

deezlfan said:


> Soooo, 3/8' LoPro isn't really 3/8". You didn't explain why 3/8 LP chain isn't 3/8th chain. I knew my old Homelite had two different spurs, but couldn't figure why. The bar will run either however. What's up with that?
> 
> Not to criticize anyone, but just saying you can't do it doesn't help the newbies. I see a lot of people jumping in on some subjects, dragging the thread off tangent and the basic question never gets answered. I have worked around *** for many years, but some subjects are just beyond my reach. Please try to remember that a lot of people here don't have 1000 muffler mods under their belts. Thanks.


Thank you, deezlfan, I am relatively new to saws and I like good explanations of why or why not.
Randy


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