Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: KilliansRedLeo on November 01, 2014, 06:21:33 pm

Title: 394 Flywheel and Coil on 3120
Post by: KilliansRedLeo on November 01, 2014, 06:21:33 pm
Read on another thread here where TLandrum suggested that a 394 FW & coil could be used directly on a later model 3120XP with a limited coil. Did anyone ever figure out if this will work?
Title: Re: 394 Flywheel and Coil on 3120
Post by: Cut4fun on November 01, 2014, 10:31:20 pm
I have never heard of anyone getting a 394 coil and fly to work in a 3120. Why would you want to anyways. The other method with 272 coil is so easy.

Maybe Ed, Adam's or someone with far more know in things like this will know.
Title: Re: 394 Flywheel and Coil on 3120
Post by: Cut4fun . on November 01, 2014, 10:44:19 pm
I think Cale bloodontheice has tried a 395 set up on a 3120 before.  Read where CC got a 395 to work. Still wonder why. Dang things rev so freaking fast with 3120 fly and 272 coil.
Title: Re: 394 Flywheel and Coil on 3120
Post by: KilliansRedLeo on November 02, 2014, 01:43:39 am
Would that be the use 272 coil and re-time the flywheel method? Got a guy with a newer 3120XP that wants to get rid of the limited coil and is looking for a bolt on method.
Title: Re: 394 Flywheel and Coil on 3120
Post by: 660magnum on November 02, 2014, 01:18:46 am
The orientation and general layout and looks of the 3 coils are alike anyway. The part #'s are different though. However, with the different shape coil from the 272, - the  372 , 357, 346, etc coil #'s only has to do with the length of the spark plug wire.

EDIT: I just noticed that my reply to your post has a time stamp 25 min earlier than your post. There's a reason for it!
Title: Re: 394 Flywheel and Coil on 3120
Post by: 660magnum on November 02, 2014, 01:23:57 am
I have a older Stihl 4140 weed whacker coil and older Stihl 025 coil beside me and their layout and shape is very much alike but their size is slightly different and they will not fit each other.
Title: Re: 394 Flywheel and Coil on 3120
Post by: mdavlee . on November 02, 2014, 01:24:30 am
If you have a friend down under they can get the 12k rpm coil. It would cost a bit more though.
Title: Re: 394 Flywheel and Coil on 3120
Post by: EHP on November 02, 2014, 09:07:29 am
394 coil setup up works , But if you have the newer 3120 that has the green coil in it the 272 coil only needds the keyway cut abit to be in correct time , if you just put the 272 coil in a green coil setup it will work pretty good but just taking a flat file to the flywheel key and filing it just abit so the flywheel advances abit more works very good, BUT remember the 3120 has a real weak connecting rod so over rpming them will end up with a broken connecting rod
Title: Re: 394 Flywheel and Coil on 3120
Post by: EHP on November 02, 2014, 09:09:08 am
and if you have a green coil setup 3120 and put a black higher rpm coil in it you will have to retime the flywheel or change the flywheel to a black coil setup
Title: Re: 394 Flywheel and Coil on 3120
Post by: Cut4fun . on November 02, 2014, 09:33:46 am
EHP pic in this thread shows how my limited black coil I pulled out looked after putting a 272 coil in it with fly key removed and retimed.  http://chainsawrepair.createaforum.com/husqvarna/husqvarna-3120-coil-swap-272/msg3272/#msg3272
Title: Re: 394 Flywheel and Coil on 3120
Post by: aclarke on November 02, 2014, 11:17:19 am
The newest -02 suffix flywheel will work with the 272 coil with original keyway location. (No indexing)   unless advancing timing for alky/nitro
Title: Re: 394 Flywheel and Coil on 3120
Post by: KilliansRedLeo on November 02, 2014, 12:39:30 pm
THANKS ADAM! That made my day, talked to the owner, the 02 suffix flywheel and a 272XP coil are already on order. Given what EHP said, I'm going to keep the saw at around 11.8-12K WFO. Think I'm going to suggest that we send the carb off to get modified for an 'H' adjustment. Any suggestions as to who to do the work?

Tim
Title: Re: 394 Flywheel and Coil on 3120
Post by: aclarke on November 02, 2014, 08:52:49 pm
Tim, easy to do.  Let me know if need a hand... or a how to
Title: Re: 394 Flywheel and Coil on 3120
Post by: KilliansRedLeo on November 03, 2014, 10:06:22 am
Quote
The newest -02 suffix flywheel will work with the 272 coil with original keyway location. (No indexing) unless advancing timing for alky/nitro

OK, Adam, let me get this into my brain, your saying that:
If the saw has the 522 89 20-02 flywheel and a limited (green) coil, the 272XP coil can be used directly without re-timing the flywheel. If the saw will be run on gas?

The 522 89 20-02 flywheel appears to that which is used on the 3120XP (EPA) saws.
Title: Re: 394 Flywheel and Coil on 3120
Post by: EHP on November 03, 2014, 12:45:16 pm
I always grind abit of the crankcase away where the coil wire come out of the coil on the 272 coil, just leaves abit more room for the coil wire
Title: Re: 394 Flywheel and Coil on 3120
Post by: srcarr52 on November 03, 2014, 12:48:49 pm
Good info on this thread boys... keep up the good work.
Title: Re: 394 Flywheel and Coil on 3120
Post by: aclarke on November 03, 2014, 03:39:12 pm
Tim, it's a plug and play conversion with the 02 flywheel+272 coil. 

If you note the magnet to key position on the new flywheel vs old, it's a big difference. Older flywheels will need to be advanced considerably.   I'll take a pic when I get home
Title: Re: 394 Flywheel and Coil on 3120
Post by: Cut4fun . on November 03, 2014, 05:31:36 pm
Pic in link above. Here is how my OLDER one looked after fly adjustment with 272 coil.  This is Ed's pic not mine.


(http://i59.photobucket.com/albums/g289/doemaster789/CH3120/Copyofindexphp.jpg)
Title: Re: 394 Flywheel and Coil on 3120
Post by: EHP on November 03, 2014, 06:40:32 pm
thats advanced just abit  ;D, but that is a pretty good gas worksaw or playsaw . Guy that owns that saw hardly ever runs it . If you were ever at one of the GTG's that was the 3120 Russ use to run
Title: Re: 394 Flywheel and Coil on 3120
Post by: Cut4fun on November 03, 2014, 07:18:50 pm
Thats how my stock 3120 was set up Ed. It had black 10.5K coil and put in 272 coil aka jonsered older coil and retimed just like in that pic.
Title: Re: 394 Flywheel and Coil on 3120
Post by: EHP on November 03, 2014, 10:37:32 pm
thats advanced lots  Kevin, Even some nitro saws are less than that but I never had any trouble running the advance at this amount
Title: Re: 394 Flywheel and Coil on 3120
Post by: bloodontheice on November 04, 2014, 02:19:46 pm
I think Cale bloodontheice has tried a 395 set up on a 3120 before.  Read where CC got a 395 to work. Still wonder why. Dang things rev so freaking fast with 3120 fly and 272 coil.

We went with a 394 or 395 because I had bought new 272 coil that was a dud, no spark outta the box.
So I had a spare 394/395 coil and figured with was worth a shot, got it to work and it's been on there for 5
years now.
Title: Re: 394 Flywheel and Coil on 3120
Post by: Cut4fun . on November 04, 2014, 02:22:22 pm
I think Cale bloodontheice has tried a 395 set up on a 3120 before.  Read where CC got a 395 to work. Still wonder why. Dang things rev so freaking fast with 3120 fly and 272 coil.

We went with a 394 or 395 because I had bought new 272 coil that was a dud, no spark outta the box.
So I had a spare 394/395 coil and figured with was worth a shot, got it to work and it's been on there for 5
years now.

Cale what flywheel with the 394 395 coil?  I am asking because I figure others will want to know.
Title: Re: 394 Flywheel and Coil on 3120
Post by: bloodontheice on November 04, 2014, 03:13:07 pm
Pretty sure it's the stock 3120 flywheel, it's been so long I can't remember.