3120 Spice Up thread

[Postrip]

Rightio
I will order one of the AM 272 coils

Are the AM 3120 coils for newer saws with a different flywheel are they?

The flywheel off the 3120k is a direct fit with a 2 post coil.
However the 3120k has a green 2 post coil,which is still limited.
You can use the 3120k flywheel with a 272xp coil perfectly.

 

[Brewz]

The flywheel off the 3120k is a direct fit with a 2 post coil.
However the 3120k has a green 2 post coil,which is still limited.
You can use the 3120k flywheel with a 272xp coil perfectly.

I don't like my chances of finding a 3120K flywheel so I will get you to mod the flywheel on the saw and will order a 272 coil of evilbay

I just sent you a PM

 

[Adirondackstihl]

Modding the flywheel for a 272 coil is not necessary

 

[Brewz]

Modding the flywheel for a 272 coil is not necessary

I am not going to discredit any discussion here but randy and postrip have both said it needs a new keyway cut, and I know they are both well experienced with 3120's.

Where are you coming from here mate?
More details

 

[Postrip]

I am not going to discredit and discussion here but randy and postrip have both said it needs a new keyway cut, and I know they are both well experienced with 3120's.

Where are you coming from here mate?
More details

That is True Tony, some guys glue/loctite the flywheel in place.
The taper on the crank is what keeps the flywheel held tight, the key way is only for timing purposes.
In the racing arena , I have seen many 3120's backfire and cutout, due to the flywheel slipping out of alignment on the crank.
It's a personal preference, but I've never had 1 slip once , by relocating the key to the new position to suit the 272xp coil.

 

[Brewz]

Ah yes.
The thought never crossed my mind because I wouldn't want to run it without a key.

It will be a tree service work saw so reliability is paramount.
Also, having the key as a reference if the flywheel needs to come off again is going to make life easier.

I will get it in the mail for you later in the week

 

[Nitroman]

That is going to be a killer saw when finished.

 

[Brewz]

That is going to be a killer saw when finished.

I sure hope so

 

[Brewz]

What would be a safe max no load rpm for a 3120?

I know I was told to keep the Stihl 084 to around 12500 rom due to its coat hanger for a crank rod

 

[Brewz]

272 coil fitted.
I took the flywheel job on myself with some advice from @Postrip and added the new keyway.

Bolted it all back together and it kicked up easy, runs nice and snappy and pulls about 12800 rpm 4 stroking at WOT