limited coil on 3120

[zr900]

Would a 1997 3120 have a limited coil?


Can you get unlimited coils still?

What is good compression on a used 3120?

 

[B_Turner]

Would a 1997 3120 have a limited coil?


Can you get unlimited coils still?

What is good compression on a used 3120?

I believe all 3120s limited.

I believe the limit went from around 11.5 K to 9.6 k here in the US around 2001.

It's a combination coil, flywheel. You can still get the older style coil and flywheel. Older coil black and newer coil green.

My own hunch is that the timing changed in the green coil setup, but I can't find hard data for that (slightly advanced).

I believe the fixed jet size has been increased several times over the years as well. (Only very early models were adjustable.) Current size is 1.12mm in the US and 1.16 mm non EPA.

StevetheKiwi is one of the main sources for 3120 info.

 

[stevethekiwi]

Hi Bill!


You are correct on all points. The date varies from country to country...

Dont forget Black coil models also have a bigger jet.

Good info from Romeo - the 272 coil fits, and sings a bit higher.


STK

 

[B_Turner]

Good info from Romeo - the 272 coil fits, and sings a bit higher.


STK

Which flywheel does the 272 coil work with? I am guessing the flywheel that goes with the black coil?

 

[funky sawman]

A minimum compression that I would live with is 130# cold. All the new ones I tested are 145-155# at 2060' above sea level and 29.95 inches barometric pressure at 75 degrees temp.

 

[stevethekiwi]

Which flywheel does the 272 coil work with? I am guessing the flywheel that goes with the black coil?

ill let ya know once ive fitted one! got a few spare here......

 

[B_Turner]

Was running my 3120 this morning (50 incher, I love big bars) and when I went to swap in a clean air filter to put it away I noticed (for the first time) that the two rubber/foam plugs that cover the carb bolt recesses don't fill the cavities.

This is where the bottom of the air filter makes a seal, so I noticed there are gaps. Course solution is simple with some more foam, but this common on the 3120?

Basically, the rubber plugs are not big enough as came with the saw.

 

[stevethekiwi]

Was running my 3120 this morning (50 incher, I love big bars) and when I went to swap in a clean air filter to put it away I noticed (for the first time) that the two rubber/foam plugs that cover the carb bolt recesses don't fill the cavities.

This is where the bottom of the air filter makes a seal, so I noticed there are gaps. Course solution is simple with some more foam, but this common on the 3120?

Basically, the rubber plugs are not big enough as came with the saw.

Bill... i think you may need to have a look at your 3120 IPL, or maybe im not understanding you correctly?

 

[B_Turner]

Bill... i think you may need to have a look at your 3120 IPL, or maybe im not understanding you correctly?

Steve,

I think the parts I am referring to are part number 503 14 47 01. Pair of foam plugs that are designed to fill the cavities below the air filter where the air filter sits.

Am I misunderstanding? Looked to me like the plugs were both undersized and so the bottom of the air filter would not seal right as is. I added a small about of foam to each one to fill the gaps.

Maybe I had been breathing too much 2 stroke exhaust?

 

[stevethekiwi]

Steve,

I think the parts I am referring to are part number 503 14 47 01. Pair of foam plugs that are designed to fill the cavities below the air filter where the air filter sits.

Am I misunderstanding? Looked to me like the plugs were both undersized and so the bottom of the air filter would not seal right as is. I added a small about of foam to each one to fill the gaps.

Maybe I had been breathing too much 2 stroke exhaust?

AH ok i see where your going. You would think they had a better system than that... foam sounds like a good idea

 

[Wet1]

Where oh where is thou Romeo????

Steve (or Romeo),

Can you confirm the 272 coil works on the 3120 and if so, have you had a chance to find out which flywheel(s) work with it yet? How do the advance curves compare?

Also, I'm not familiar with the "fixed jet" in the 3120, is it permanently "fixed" or can it be changed or modified.

What other basic changes can be made to wake this thing up? Muffler mod?





Lastly, I wonder why Husky advertises "Maximum recommended engine speed 12000 rpm" when it's limited at 9.6k?

 

[stevethekiwi]

Steve (or Romeo),

Can you confirm the 272 coil works on the 3120 and if so, have you had a chance to find out which flywheel(s) work with it yet? How do the advance curves compare?

Also, I'm not familiar with the "fixed jet" in the 3120, is it permanently "fixed" or can it be changed or modified.

What other basic changes can be made to wake this thing up? Muffler mod?





Lastly, I wonder why Husky advertises "Maximum recommended engine speed 12000 rpm" when it's limited at 9.6k?

havnt had a chance to fit the 272 coil yet... will be interesting as the FW is different between epa / non epa, i imagine it will go on the non epa without an issue.

carb jet - fixed and not adjustable, but definately replaceable. to change your carb to non-epa, whip the top off it, remove old jet, and screw in the new 1.16mm jet.

Send a PM to romeo about the coil / flywheel, im pretty sure he's done it before on one of his race saws. if in doubt, just fit a 3120 non epa coil and FW + 1.16mm jet

 

[B_Turner]

Hey Steve,

A buddy bought just bought a brand new 3120 and from the first time he ran it there is alot of black oily looking liquid coming from behind the muffler onto the fins (toward the compression release). Black liquid still visibly running back from the muffler after maybe half a dozen tanks.

My 3120 seeps a little bit at that location, but nothing like this.

You have seen lots of 3120s, is this common and what could be done about it?

 

[stevethekiwi]

Hey Steve,

A buddy bought just bought a brand new 3120 and from the first time he ran it there is alot of black oily looking liquid coming from behind the muffler onto the fins (toward the compression release). Black liquid still visibly running back from the muffler after maybe half a dozen tanks.

My 3120 seeps a little bit at that location, but nothing like this.

You have seen lots of 3120s, is this common and what could be done about it?

if its coming from behind the muffler, its loose. if its new id say it wasnt tightened on Pre Delivery. whip it off and clean / inspect it, then re fit. tighten, run it, tighten. i say whip it off because its easier to clean the fins, and there may be a burr or something thats stopping the muffler from seating. if you clean everyting, its easier to see if you've fixed the problem!

oh yeah - warranty!!!

 

[B_Turner]

if its coming from behind the muffler, its loose. if its new id say it wasnt tightened on Pre Delivery. whip it off and clean / inspect it, then re fit. tighten, run it, tighten. i say whip it off because its easier to clean the fins, and there may be a burr or something thats stopping the muffler from seating. if you clean everyting, its easier to see if you've fixed the problem!

oh yeah - warranty!!!

The muffler bolt swere snug, something not seating.

I think all the 3120s I have seen weep a little on the right side behind the muffler, so I thought maybe you'd say just to live with it.

This one is much worse than mine, and I think maybe he should take it back to the dealer to avoid warranty issues. Might seem picky, but I think for $1500 a saw should at least be pretty for a while.

 

[stevethekiwi]

The muffler bolt swere snug, something not seating.

I think all the 3120s I have seen weep a little on the right side behind the muffler, so I thought maybe you'd say just to live with it.

This one is much worse than mine, and I think maybe he should take it back to the dealer to avoid warranty issues. Might seem picky, but I think for $1500 a saw should at least be pretty for a while.

Ive had a couple do it before, but only in very small amounts. for some reason they stopped doing it after a few tanks...

 

[B_Turner]

AH ok i see where your going. You would think they had a better system than that... foam sounds like a good idea

STKW has straightened me out on this. Upon looking at the 3120 air filter setup more carefully, I can see that the filter seals towards the outside edge near these foam filled holes.

So no real problem exists with the design as is.

 

[SawTroll]

STKW has straightened me out on this. Upon looking at the 3120 air filter setup more carefully, I can see that the filter seals towards the outside edge near these foam filled holes.

So no real problem exists with the design as is.

Big surprice, as it is a fairly new model, only about 20 years old........:biggrinbounce2:

I guess the 3125 (or 5125) isn't far away, as the cut-off saw alredy is out.

 

[B_Turner]

I have in my possession two 3120s right now, both saws are recent EPA versions. One has had the coil and flywheel swapped to the black setup the other the stock green coil.

Here's my question: Anyone suggest a really simple way to compare top speed ignition timing between saws to see if Husky really did slightly advance the lower limited setup?

I don't really want to have to find TDC, etc on the saws or spend a lot of time on it as I'm pretty busy right now. Maybe pop the top cover on each and use a non adjustable timing light (that's all I have) to somehow assess how the timings compare? All I'm trying to do actually is see whether or not the "final" timings are the same or not.

Seems like you clever folks out there might have some simple approach.

 

[B_Turner]

To follow up on this thread, inspection of the muffler showed the muffler seat had a low spot (on the muffler, that is). Tried lapping it out, but not enough steel on muffler to fix.

A replacement muffler (warranty) had nearly the same problem with a very low spot. Very obvious using a straightedge or flat plate.

The dealer concurred and ordered another replacement muffler and this one was almost flat. Tried itand it stilled leaked a little. A little hand lapping and it now seals fine. The original one shot a stream of black goo out within seconds of running it which made a mess as well as being kind of stinky on the muffler.

So now I've inspected four new 3120 mufflers and they all had the same lowspot to some degree. Centered on the opening on the up side. The other side of each muffler was flat (which is what you want).