3120XP rebuild (pics)

[MCW]

whats the difference between the non epa and the epa versions? is the muffler different? catalytic muffler?

I think it is simply tuning. The 3120/880's are pretty old designs now and haven't been changed for a long time. They really are just tough old dinosaurs when compared to their smaller cousins. As far as I am aware it is simply tuning and the rev limit to help make emissions - to meet emissions otherwise will take a major overhaul and redesign. Not sure if you guys get cat mufflers or not?

 

[husq2100]

thanks Matt, If the saw has been set for 25-1 then thats where id run it....the ratio is not so much the problem, but the tune to ratio. I can understand the 660 guys changing as they can tune to suit and most loggers would tune their saws. Funny thing, in the OM for my mates 5100s that I imported for him, it stated to use dolmar oil 50-1 any other oil at 25-1 (like their's were better) but no addressing tune to ratio. My experience is with the K series saws with the splined carb needles, now most concrete guys wouldnt know about tuning, let alone have the tool, but some techs are telling them to run 25-1 instead of the 50-1 in the manual....

 

[husq2100]

I think it is simply tuning. The 3120/880's are pretty old designs now and haven't been changed for a long time. They really are just tough old dinosaurs when compared to their smaller cousins. As far as I am aware it is simply tuning and the rev limit to help make emissions - to meet emissions otherwise will take a major overhaul and redesign. Not sure if you guys get cat mufflers or not?

I wonder if there has been suttle port timing changes like the 660 over the years??

 

[WidowMaker1]

Aussie versions don't have a Cat muffler just a baffle (which can be opened up into a Jungle version easily) I'm not shore if The EPA/US saws have a Cat Muffler ?? ...There is a Jungle version muffler that's basically a open flow "No baffle" design that comes standard on 3120's in certain regions! In Aus we get a Baffle for Noise pollution. and saws in OZ aren't hampered by Air pollution like The US .....The dealers Ive talked too, are saying the Limited H screw on the 3120's is basically a fail safe ,because of people trying to tune there saws with out having any tuning knowledge, and they tend to cook there saws by tuning to lean without realizing ...I guess husky got sick of replacing/repairing badly tuned saws.

 

[TreeSurfer]

the one on this 3120 i rebuilt has no baffle in the muffler.

 

[jbighump]

didnt some one do a test and proved that 50:1 ran cooler than 32:1,because the gas cools better than oil,,,i run 50:1 ultra and have no problems.....if it were me i would have pulled the seals and flused the case out to get all that aluminum out from behind the bearing

 

[TreeSurfer]

did that, flushed it with gas

 

[MCW]

Funny thing, in the OM for my mates 5100s that I imported for him, it stated to use dolmar oil 50-1 any other oil at 25-1 (like their's were better) but no addressing tune to ratio. My experience is with the K series saws with the splined carb needles, now most concrete guys wouldnt know about tuning, let alone have the tool, but some techs are telling them to run 25-1 instead of the 50-1 in the manual....

Yeah I've read that ratio bit before with oil. The old my oil is better than your oil trick

I wonder if there has been suttle port timing changes like the 660 over the years??

Not sure mate. I'd have to honestly say though that the 3120 and 880 would have had the least amount of changes compared to any other pro saw over the years. Except for maybe an Oleo Mac, they look like they're still stuck in the 70's