Basic 3120xp Mods

[B_Turner]

An excellent read here. I'm bumping this since I will be working on a 3120 soon.

I'd love to hear what sort of gains you get before you muffler mod.

I know gains will be muted, but I'm very curious anyway as I"ve considered having one of my 3120s mildly ported without touching the muffler.

Yeah, I know I'm a broken record on this....

One of the challenges will be jetting the HS esp if it has a rev limited coil. I'd suggested buying an extra jet as they are less than $3.

ALso I hope you do progessive vids as you often do.

 

[blsnelling]

This saw is about 4 years old. It was ported, etc, when new. An offset flywheel key was used, which sheared right away, and it hasn't run right since. So it's a brand new saw that's been setting for 4 years. Hopefully I won't find a bag of worms and a carb cleaning and it'll be back in shape. I don't yet know if it has the low RPM coil or not. I can't see leaving it with a 9,600 RPM coil. If ported, it should consistently pull well more than that in the wood.

 

[B_Turner]

This saw is about 4 years old. It was ported, etc, when new. An offset flywheel key was used, which sheared right away, and it hasn't run right since. So it's a brand new saw that's been setting for 4 years. Hopefully I won't find a bag of worms and a carb cleaning and it'll be back in shape. I don't yet know if it has the low RPM coil or not. I can't see leaving it with a 9,600 RPM coil. If ported, it should consistently pull well more than that in the wood.

Even my stockers like best to pull 9.5- 10.2 in the wood, loaded with a big bar. Right above where the green coil cuts out!

I think the main reason the 3120 gets such a bad rap is that low limit since 2000. Otherwise they are a smooth, and strong saw.

 

[brncreeper]

Mine is on it's way back from timberwolf, I should get it in a few days. I can't wait!:hmm3grin2orange:

 

[blsnelling]

Mine is on it's way back from timberwolf, I should get it in a few days. I can't wait!:hmm3grin2orange:

Do you know what he did with the limiter and carb?

 

[brncreeper]

I replaced the limited 9500 rpm “green” coil before I shipped it, I sent along a spare WG6 carburetor for him to mod. I believe besides boring the carbs throat he drilled the jet to get the correct spark plug color.

 

[capeferrelo]

Walbro WG8, etc...

Hi All,

I've been considering a 3120 as a milling powerhead, and wondering about finding a pre-EPA unit, or fiddling with a current one, or just seeing if the stock RPM and fuel limits will work for milling.

So, the thread has been very interesting. I have been looking up the WG8 carbs online, and see they are used in a lot of different applications such as paragliders, etc...I am sure some or most of you know that already.

I did find some interesting sites, notably Walbro's website which lists a new WG8 for aftermarket sale, with HS adjuster (presumably for those users who have gliders or karts or whatever) for $96.31 :
http://wem.walbro.com/walbro/partnumbersearch.asp?ItemNumber=WG-8-1&ManuItemNumber=&submit1=Go

http://wem.walbro.com/walbro/product2.asp?partnum=WG-8-1&Series=WG

Also found a site for a powered hanglider which has a nice write-up on WG8 disassembly:
http://www.wind-drifter.com/technical/wg8walbro.php

I have not seen the fixed carb in a 3120, but if the HS adjuster screw is simply blocked off with a plug, I would imagine that someone with some experience in modding carbs, especially something like Webers, or a good speed shop, could easily modify the unit to accept an adjuster (which appear to be availble from Walbro, or maybe cannibalized from another Walbro carb.

If noone's seen these sites before, I hope you enjoy...and if anyone is looking at their 3120 carb, can you verify the adjust port being simply blocked, or never machined? Again, I think a good machinest could fix that.

I would like to hear ideas, feedback, etc...I've had conflicting opinions about what is better as a milling head....395 or 3120. I have a 288xp that I love and use for felling and bucking (though I am always in the mood for another, or a 262 or 272 if anyone out there is unloading saws in the future), but I would rather keep that saw for cutting, not milling.

Cheers,

Steve

 

[boo]

is the WG-6 the carb to use?
Walbro shows the WG-3-1 with part#102-3077 and WG-5-1 with part#102-3062.
Both are for partlist#40 (HS adjustable)
http://wem.walbro.com/walbro/group2.asp?FamilyName=WG

 

[ritchie.426]

When I got the 3120 going

it was running 13500 (from memory) with a 28" bar. I run it at 13000 free reving, sits on 12 in a log, seems to handle it well.

Goes hard now.....!!

Got a couple of macrocarpas to drop shortly so I will put the 36" bar on and see how she goes, might be able to ge t a vid as well!:greenchainsaw:

 

[blsnelling]

You will not find a new WG carb with a H needle. The WG-8 was mentioned a couple posts up. If you open the exploded view, and go down to the high speed needle, you'll see there's just -----, no PN. It does not have one. There is not a plug in the carb, it's cast solid. Additionally, if there were a H needle there, it would be directly covered by the air filter base, hitting the needle where it comes out of the carb. So even if you find an old carb with a H needle, it will not likely just bolt onto your 3120.

Your best bet is to keep reeming out a jet until you get it right. It's time consuming, but very easy to do.

 

[gogo_78]

Does anyone know any source for 1.16 non epa jets nowadays?

 

[Matt@wiscotreeteam]

Any updates on parts availability in the US for these mods?