# 076 v 090 v 880 v 3120



## john inglis (Jan 12, 2010)

hi ,what are the merits of the saws compared to each other , i have both the 076 and 090 but wonder if a modern saw would be better in a mill setup . ive owned an aussie made forestmill ( two circular blades at right angles driven by vw motor ) but would like a compact mill i can get to logs on site


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## BobL (Jan 12, 2010)

john inglis said:


> hi ,what are the merits of the saws compared to each other , i have both the 076 and 090 but wonder if a modern saw would be better in a mill setup . ive owned an aussie made forestmill ( two circular blades at right angles driven by vw motor ) but would like a compact mill i can get to logs on site



They are all very good milling saws. I have an 076 and an 880 and have used a 3120 for about 2 weeks of milling.
In stock form

076: 9500 rpm carby limited, good torque, reliable, harder to get parts, heavish, best exhaust location
090: 8000 rpm limited, torque monster so can run can run lower rakers and bigger sprocket, very heavy, parts still available.poor exhaust location.
Both these saws have an outboard clutch and the fuel cap on top of the saw so both cannot be refueled mid slab because the fuel cap is then on its side ie PITA
3120; 9500 rpm coil limited, fixed H jet, outboard clutch, Outboard chain tensioner awkward to get at while saw on conventional mil and mill mounting to bar method means clutch cover must be retained, poor exhaust location.
880: 12000 rpm coil limited. inboard clutch and chain tensioner, poor exhaust location

Depending on log size CS milling is chain speed limited so higher RPMs help. Extra torque can be translated to extra chain speed using bigger sprocket and can utilize higher cutter angles. With a small amount of finesse the 090 is still the fastest cutter in big logs, but for smaller logs nothing will beat the higher RPM saws. 

My guess is it will come down to how far you have to carry the sucker to the log. But even with the 090 you can always add wheels to a CS mill like this.


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## Brmorgan (Jan 12, 2010)

With the 090 there's also the factor of incredible vibration, especially compared to the 880 or 3120. Unless you're lucky enough to find an 090AV - in which case, well, _bite me_. LOL.


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## excess650 (Jan 13, 2010)

IIRC, the pre 2000 model 3120xp had a higher limit on the coil(like 11K or so), and at least first year production model year (1988?) had a fully adjustable carb rather than requiring jet reaming/replacing like later models. (USA models)

The 3120xp powerhead weighs some 23# which is the same as an 066 or 660 with 25" B&C.

I thought my 3120xp from the mid 1990s to be very smooth, but do most of my milling with a 066 with BB kit.


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## tomtrees58 (Jan 13, 2010)

the 076 it a big saw tom trees


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## BobL (Jan 13, 2010)

excess650 said:


> IIRC, the pre 2000 model 3120xp had a higher limit on the coil(like 11K or so), and at least first year production model year (1988?) had a fully adjustable carb rather than requiring jet reaming/replacing like later models. (USA models)


Yeah - why'd they do that?



> The 3120xp powerhead weighs some 23# which is the same as an 066 or 660 with 25" B&C.


The 880 powerhead is very similar at 22.3 lbs 



> I thought my 3120xp from the mid 1990s to be very smooth, but do most of my milling with a 066 with BB kit.


I agree it is a smooth saw.


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## john inglis (Jan 13, 2010)

hi and thank you for the tips , your right about the 090 vibes , the one i have is an av model and it still gives a reasonable tingle when you load it up . i first owned this saw about 15 years ago and sold it to a good mate of mine . i asked him about it a few weeks ago and we are doing a swap for another saw ,probably the 076 . it is interesting that a bb 660 cuts okay as i have a 660 but have left it standard so far as it already has the twin port exhaust. i would love an 880 as have used an 084 on a portable mill cutting 3' hardwood and it worked very well . i might have to part with a couple of saws and upgrade .


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## Brmorgan (Jan 13, 2010)

john inglis said:


> hi and thank you for the tips , your right about the 090 vibes , the one i have is an av model and it still gives a reasonable tingle when you load it up . i first owned this saw about 15 years ago and sold it to a good mate of mine . i asked him about it a few weeks ago and we are doing a swap for another saw ,probably the 076 . it is interesting that a bb 660 cuts okay as i have a 660 but have left it standard so far as it already has the twin port exhaust. i would love an 880 as have used an 084 on a portable mill cutting 3' hardwood and it worked very well . i might have to part with a couple of saws and upgrade .



Wow, swap an 076 for an 090AV? Guess who wins on that deal!


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## BobL (Jan 13, 2010)

Brmorgan said:


> Wow, swap an 076 for an 090AV? Guess who wins on that deal!



The former 090's owners shoulders and arms will win for sure!


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## john inglis (Jan 14, 2010)

*076 for 090*

hi , just so i dont give the wrong impression the 076 is fully sorted with an excellent bar and new 404 chain with another saw as parts ( nearly complete ) while the 090 has been a bit neglected and required a strip and cleanup and the manual oiler does not seem to be working . Engine wise it feels good and while tuning carb set up a pretty high whistle till i got mixtures sorted , compression is good and the saw has not done a lot of hard work as i owned two forest mills when i first owned this saw and while it has not been looked after (my mate loaned it to another friend who is fairly rough on alloy bits) it is quite sound engine wise . Will fit it up with 36" 404 for now and give it a good workout as soon as i find a drive cover tho i could use the broken one untill i find a good one . does anyone know if the clutch covers are weldable . have a good day guys, good talking to you . there are few cad sufferers nearby .

hi brmorgan, noticed that you have an 045 , wondered what you think of them as i have 2 in bits but all there but for muffler , have one sick one , is it worth putting one back together , dont know much about them


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## BobL (Jan 14, 2010)

john inglis said:


> hi , just so i dont give the wrong impression the 076 is fully sorted with an excellent bar and new 404 chain with another saw as parts ( nearly complete ) while the 090 has been a bit neglected and required a strip and cleanup and the manual oiler does not seem to be working .
> .
> .
> .
> ...


I doubt they are weldable but new ones are available, see
http://www.baileysonline.com/itemdetail.asp?item=QA+11066+480412&catID=313


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## Brmorgan (Jan 15, 2010)

Magnesium is weldable if you're a wizard with a TIG torch. But unless you have a close friend who meets the criteria and is willing to do the work for free or a case of beer etc., I doubt you'd end up very far ahead of buying new if you had to pay someone to do it. And afterwards you'd have to paint it anyway. Well, I guess you wouldn't _have_ to.


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## Hddnis (Jan 15, 2010)

You will need to hot soak the park in solvant to get the grease out. I have a friend that welds magnesium for me when I have a part I don't want to try myself. i.e. it has to be done right the first time. lol

He either hot soaks in solvant or bakes it in an oven. The oil that is simply part of chainsaw operation soaks into the magnesium and makes for bad welding properties. He has done some welds for me that I just touched up lightly with a sander and could not tell the part was fixed.



Mr. HE


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## Meadow Beaver (Jan 15, 2010)

Buy a Pioneer 700G then there won't be any competition.


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## Brmorgan (Jan 15, 2010)

Hddnis said:


> You will need to hot soak the park in solvant to get the grease out. I have a friend that welds magnesium for me when I have a part I don't want to try myself. i.e. it has to be done right the first time. lol
> 
> He either hot soaks in solvant or bakes it in an oven. The oil that is simply part of chainsaw operation soaks into the magnesium and makes for bad welding properties. He has done some welds for me that I just touched up lightly with a sander and could not tell the part was fixed.
> 
> ...



Yeah Magnesium is a very porous metal. Just when you think you've gotten it clean it makes you look like an idiot. I hate it because I have a hard time getting JB Weld to stick to it well.


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## Hddnis (Jan 15, 2010)

Brmorgan said:


> Yeah Magnesium is a very porous metal. Just when you think you've gotten it clean it makes you look like an idiot. I hate it because I have a hard time getting JB Weld to stick to it well.




The funny thing is that porosity should make the JB Weld stick better. But as you said, that is not always the case. 

Some of the newer Magnesium cases seem to weld and JB Weld better. I think they are using an alloy that is finer grained, not as open to absorb oil and air. It also seems a little less brittle. I might also just be imagining it since I have not conducted any scientific comparisons.



Mr. HE


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## Andrew96 (Jan 16, 2010)

I don't think your imagining it. I'm pretty good with a good tig machine but seem to be getting way better with Magnesium lately too. It seems to clean up much better. It must be something those crafty metallurgy guys are doing to keep the porosity down. I'm not really doing anything differently but get better results.


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## Trever (Nov 17, 2010)

Brmorgan said:


> Magnesium is weldable if you're a wizard with a TIG torch. But unless you have a close friend who meets the criteria and is willing to do the work for free or a case of beer etc., I doubt you'd end up very far ahead of buying new if you had to pay someone to do it. And afterwards you'd have to paint it anyway. Well, I guess you wouldn't _have_ to.



+1 TIG with Magnesium rod I am pretty sure.

Trever


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## 820wards (Nov 18, 2010)

Brmorgan said:


> Yeah Magnesium is a very porous metal. Just when you think you've gotten it clean it makes you look like an idiot. I hate it because I have a hard time getting JB Weld to stick to it well.




I have tig welded magnesium automotive parts that had oil residue and it will not weld if it's not cleaned of all oil. If it's not clean when you strike an arc, it blows the magnesium or aluminum onto the 2 percent tungsten tip specific for welding magnesium or aluminum. 

I have a liquid soap cleaner I bought 20 years ago that was made for cleaning aluminum/ magnesium. Cleaned with this solution and hot water the parts can be welded. It is no longer made so I bogart what I have left. I've been experimenting with a mixture of Simple Green and muriatic acid with pretty good results. Too much acid in the solution though will etch the alloys. 

jerry-


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## gemniii (Nov 18, 2010)

Just a note on the "rev limited 880"
blsnelling on the chainsaw forum mentioned in a recent thread about swapping out parts from an earlier saw (088?) to bypass that.


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## Karl Robbers (Nov 18, 2010)

*welding stihl chainsaw components*

I know that I will possibly start a riot, but heres my 2 cents worth anyway.
Magnesium welds quite nicely with the Tig process. However. The alloy that Stihl chainsaws are made from contains so much assorted crap that it pops, farts and flames when you weld it and is very prone to porosity, even when cleaned. I have welded many different chainsaw components from many different manufacturers, ( I am a certified welder) and to be honest Stihl is the worst of the lot.
Come to think of it they are the only ones that I have ever had to repair the front handles on too.
Stihl may have some good features, but their weldability certainly isn't one of them:biggrinbounce2:
Back to the subject while 3120's and 880's may be coil limited to 900 and 12000 rpm respectively, don't forget where their maximum horsepower lies, in the case of the 3120 at least it is at, you guessed it, 9000rpm. The 880 would be similar I imagine.
Just something to think about.


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## Meadow Beaver (Nov 18, 2010)

Karl Robbers said:


> I know that I will possibly start a riot, but heres my 2 cents worth anyway.
> Magnesium welds quite nicely with the Tig process. However. The alloy that Stihl chainsaws are made from contains so much assorted crap that it pops, farts and flames when you weld it and is very prone to porosity, even when cleaned. I have welded many different chainsaw components from many different manufacturers, ( I am a certified welder) and to be honest Stihl is the worst of the lot.
> Come to think of it they are the only ones that I have ever had to repair the front handles on too.
> Stihl may have some good features, but their weldability certainly isn't one of them:biggrinbounce2:
> ...



An MS880 and 3120xp can both be easily changed to be _non_-rev limited.


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## gemniii (Nov 18, 2010)

Meadow Beaver said:


> An MS880 and 3120xp can both be easily changed to be _non_-rev limited.



Why are saws rev-limited? EPA?


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## BobL (Nov 18, 2010)

gemniii said:


> Why are saws rev-limited? EPA?



I always thought it was to reduce the possibility of engine damage. If the saw is tuned on the lean side it will rev higher than it should so it can damage the engine or even seize the saw if it used for too long in that state. It's not foolproof but apparently it saves saws.

Just removing rev limitation from a CS does little or nothing for their stock performance since they should already be operating at peak power at somewhat fewer RPM than their limit. The latest 3120 and 880 are rev limited to 9500 and 12000 rpm, with peak power at 9000 and 9600 respectively. The only way to increase the RPM at which max power is developed requires things like porting and/or muffler modding and if required rejetting the carby. 

In the case of a rev limited 3120 there is only 500 rpm above the max power RPM to play with so things like a muffler mod which might make it breathe more easily might also push the theoretical max power RPM close to 9500 but having the saw operating at close to its rev limit is not ideal as it just won't develop it's full power. This is when it makes sense to remove the rev limiter. However, the 3120 also has fixed H setting so that may be enlarged as well otherwise the saw may be running too lean.

With the 880 you have 2400 rpm above the max power RPM to play with as well as having a variable H screw. This means it can accommodate mild muffler and other mods without the need for removing the rev limiter.

Max rpms are somewhat meaningless in the cut, it's the rpm at max power that counts.


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## mtngun (Nov 18, 2010)

There have been reports of late model 3120's hitting the limiter while milling, and sometimes at pretty lame speeds. Apparently, some of the limiters are set pretty low. 

Saws don't necessarily run at the rpm that makes max power, just as your van doesn't necessarily run at the rpm that makes max power. 

The motor can exceed the max power rpm as long as there is a surplus of power. Higher chain speeds require more power, at some rpm the power required to spin the chain equals the power produced, that is the equilibrium RPM.


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## Hillbilly3995 (Nov 18, 2010)

820wards said:


> I have tig welded magnesium automotive parts that had oil residue and it will not weld if it's not cleaned of all oil. If it's not clean when you strike an arc, it blows the magnesium or aluminum onto_ the 2 percent tungsten tip specific for welding magnesium or aluminum. _
> jerry-



Jerry, go back at look at your electrode box. its not 2 percent tungsten...

its mostly tungsten, the 2 or .2 or .02 percent is thorium, a radioisotope
you should be very cautious when sharpening these so as to minimize exposure and risk of inhalation of any debris. (its radioactive)

I know an old man (well, older than me) that replaced 40% of a magnesium boat prop blade with a tig torch,
when he was finished it looked and worked like a new one.


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## mtngun (Nov 18, 2010)

gemniii said:


> Why are saws rev-limited? EPA?


In addition to what BobL said, the 120cc saws in particular are known to turn into a grenade if you over rev them. They just have a lot of rotating mass. Member Bob Steuwe blew up his 084 not so long ago by over revving, and not over revving that much, either.


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## BlueRider (Nov 18, 2010)

Bob- nice explanation of the 4 saws. If you edit your original post to add the Displacement I think it would make an exclent sticky. There seems to be a questin every month or two asking about one or more of those four saws.

As for the rev limiter on the 075 it is probably the easiest of the batch to bypass. The rev limiter is a pressue activated jet that dumps fuel into the carb. To by-pass it all you need to do is remove the screw and place a small piece of a soda can under the screw.


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## BobL (Nov 19, 2010)

BlueRider said:


> Bob- nice explanation of the 4 saws. If you edit your original post to add the Displacement I think it would make an exclent sticky. There seems to be a questin every month or two asking about one or more of those four saws.
> 
> As for the rev limiter on the 075 it is probably the easiest of the batch to bypass. The rev limiter is a pressue activated jet that dumps fuel into the carb. To by-pass it all you need to do is remove the screw and place a small piece of a soda can under the screw.



Yeah I have seen that posted before about the 076, have you done it and what if so what difference does it make?


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## 820wards (Nov 23, 2010)

Hillbilly3995 said:


> Jerry, go back at look at your electrode box. its not 2 percent tungsten...
> 
> its mostly tungsten, the 2 or .2 or .02 percent is thorium, a radioisotope
> you should be very cautious when sharpening these so as to minimize exposure and risk of inhalation of any debris. (its radioactive)
> ...



My brother and I had a ski boat and I fixed our props many times from hitting rocks. I guess I'm old... 58

jerry-


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## 046 (Feb 24, 2011)

lots of great info in this thread!


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## MCW (Feb 28, 2011)

BobL said:


> 3120; 9500 rpm coil limited, fixed H jet, outboard clutch, Outboard chain tensioner awkward to get at while saw on conventional mil and mill mounting to bar method means clutch cover must be retained, poor exhaust location.
> 880: 12000 rpm coil limited. inboard clutch and chain tensioner, poor exhaust location[/IMG]



Are you sure your mate's 3120 is limited that low Bob? My 2 year old Australian delivered 3120 is limited to 12,500rpm and the US versions are limited to 9,800rpm from memory. The main reason I purchased my 3120 in Australia unlike all of my other saws (sourced from the US due to price) was because of the rpm limit and no EPA garbage.
I'd say if your mate bought his 3120 in Australia and it is limited to the lower rpm's somebody has done a sneaky and imported a US saw to sell.
The US 880's are also limited less than the Aussie versions. Just like the Aussie delivered 660's have the high output oiler and dual port muffler (plus more power).

By the way, I haven't been milling lately but thought I'd drop in on the milling forum


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## smokinj (Feb 28, 2011)

My 880 is stock and limited to 12500. Milling Hickory black locust and walnut. Not really thinking of modding it at all. Chain that stays sharp all day long now that would be a Sweeet Modd.


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## MCW (Feb 28, 2011)

smokinj said:


> My 880 is stock and limited to 12500. Milling Hickory black locust and walnut. Not really thinking of modding it at all. Chain that stays sharp all day long now that would be a Sweeet Modd.



Is your 880 an older model mate? Sorry I should have added newer model 880's when I mentioned the lower rev limit. I know that some of the later US delivered 880's are limited to around 10,000rpm and I think Brad Snelling had video of it. The 3120's and 880's are turds with the lower limiters.


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## BobL (Feb 28, 2011)

MCW said:


> Are you sure your mate's 3120 is limited that low Bob? My 2 year old Australian delivered 3120 is limited to 12,500rpm and the US versions are limited to 9,800rpm from memory.


No I am not sure, I'm just going by the manual. Next time I'm down his way I'll get the tacho out.




> By the way, I haven't been milling lately but thought I'd drop in on the milling forum


 
Neither have I - too bloody hot and too much else on the go.


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## smokinj (Feb 28, 2011)

MCW said:


> Is your 880 an older model mate? Sorry I should have added newer model 880's when I mentioned the lower rev limit. I know that some of the later US delivered 880's are limited to around 10,000rpm and I think Brad Snelling had video of it. The 3120's and 880's are turds with the lower limiters.


 
It was bought last May. Who knows how long it set. Manuel says 12,500. Sorry Just manuel out its "11,500"


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## MCW (Feb 28, 2011)

BobL said:


> No I am not sure, I'm just going by the manual. Next time I'm down his way I'll get the tacho out.
> 
> 
> 
> ...


 
Yeah I'll check my 3120 manual when I get home but I'm pretty sure mine says the lower rev limit too despite mine taching out higher. I'm the same in regard to heat and workload mate, got a few guys wanting logs milled but have had too many felling jobs taking priority


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