Husqvarna 3120xp ignition timing for unlimited 272xp coil

[Benwa]

So I have a 1997 3120XP that has the older style black coil. I'm looking to install a 272 unlimited coil. I have not yet, but will, run the 3120 in current configuration to check on where ignition timing is set at before tdc stock. I have no problem reclocking or rebroaching the early style flywheel to work with the 272 coil.

My question is for those that have done this with the older flywheel. Do you know how many degrees you need to advance the 3120 flywheel to match the 272 coil? I've searched, but haven't found the pertinent info.

If not, I'll sit down and do some comparing, figuring, etc. If I had a whole 272xp saw on hand as reference, I wouldn't even be asking. At any rate, I figured I'd save myself some time if somebody already had the info on hand. If not, I'll figure it out. Thanks in advance for any info.

 

[Canadian farm boy]

About this much. Lol.
Idk the exact number of degrees.
I put a line straight between the center of the starter pawl bolts. Where the line crosses the crank bore in the FW is where you make the new keyway. You can fine tune it by filing the key.
I can’t take all the credit for figuring this out. I had some guidance from a few other guys that had done this previously.

 

[Benwa]

About this much. Lol.
Idk the exact number of degrees.
I put a line straight between the center of the starter pawl bolts. Where the line crosses the crank bore in the FW is where you make the new keyway. You can fine tune it by filing the key.
I can’t take all the credit for figuring this out. I had some guidance from a few other guys that had done this previously.View attachment 315670

Thank you for taking the time! This is EXACTLY what I'm after. I was just after a baseline. I can run it with a timing light to fine tune it. Thanks so much. Major time saver! Always amazes me, stuff like this........... it's like it was meant to be. It SHOULDN'T be that simple....... but IT IS!

 

[Moparmyway]

Not too sure about anyone else, but my black coil equipped 3120 needed re-indexxing. My new green coil 3120 did not

I switched both to the unlimited coil


Unlimited coil wire screw

Old style coil wire screw

Unlimited coil on left, original coil on right


Old style flywheel on top, new style on bottom. Flywheel slots are lined up to show the difference in magnet placement


Old style coil, new limited coil (green) then unlimited coil


**EDITED to correct the information **
Thanks Kev !!!

 

[Woodslasher]

I read where some guy cut the third "leg" off a limited coil and it will "unlimit" it, but I haven't actually tried it so I don't know if it's true.

 

[huskihl]

Not too sure about anyone else, but my black coil equipped 3120 didnt need re-indexxing. My new green coil 3120 did

I switched both to the unlimited coil


Unlimited coil wire screw
View attachment 315729
Old style coil wire screw
View attachment 315730
Unlimited coil on left, original coil on right
View attachment 315731

Old style flywheel on top, new style on bottom. Flywheel slots are lined up to show the difference in magnet placement
View attachment 315732

Old style coil, new limited coil (green) then unlimited coil
View attachment 315733

You had the wrong coil or fw on it to start then. The 272 coil times exactly like the green coil. I did have one that came in with mismatched parts. It would run alright, but it was popping pretty good in the cut

 

[Moparmyway]

You had the wrong coil or fw on it to start then. The 272 coil times exactly like the green coil. I did have one that came in with mismatched parts. It would run alright, but it was popping pretty good in the cut

I had a little more time to look at the pictures…..
I’ve got it backasswards ……..
The old one runs no keyway so it’s re-indexxed.


The new one was a direct swap

Sorry for the confusion men !!