Husqvarna 51/55 Advanced Timing Questions

[Bridog]

Hey Guys,
I have a next to new Husqvarna 51 that I'm working on. It was a "non-running" saw that literally just needed new mix to get it going again. I'm leaving the stock 51 piston/cylinder as it is in almost new condition but am doing a few mods to give it a little more pep. It only has 135lbs compression which seems really low for the condition it is in.

To increase compression, I'm eliminating the cylinder gasket as oem is 0.032-0.036 squish. Taking the gasket out narrows the squish up to .022-.024 according to my measurements. I'm also replacing the piston ring with an oem ring while I'm in there.

I am moderately opening up the muffler and polished the exhaust walls slightly to get rid of a few rough spots. No porting.

I would like to advance the timing slightly. This is where my questions come in. This saw has an integral key that is part of the flywheel.

Which side of the key is supposed to be filed to advance the timing? Is advanced timing rotating the flywheel more clockwise or counter clockwise?

How much are guys filing away?

If you have done this has the return been beneficial?

Thanks, Brian

 

[happysaws]

To advance the timing, you will want to turn the flywheel clockwise.

I remember hearing that .020" off the key will advance the timing around 5°... But I could be mistaken with that number.

Edit:
I have advanced the timing around 7° from stock on on my Lancaster 820, and it helped with power a good bit.

 

[merc_man]

Is clockwise not timing retard? If i remember rite from looking at flywheel side, flywheel has to go counterclockwise.
So with key at 12 oclock take material off key side that is tward front of saw. ( bar chain direction).



Sent from my SM-J320W8 using Tapatalk

 

[happysaws]

Is clockwise not timing retard? If i remember rite from looking at flywheel side, flywheel has to go counterclockwise.
So with key at 12 oclock take material off key side that is tward front of saw. ( bar chain direction).



Sent from my SM-J320W8 using Tapatalk

You are correct, I was thinking backwards.
Either the stator has to be moved clockwise to advance the timing, or the flywheel counterclockwise.

 

[Little Al]

Looking at flywheel fins (Outside) it needs to be moved counter clockwise So looking up the flywheel taper at the key at 12 o'clock metal removed from 5 past (clock face ) side of the key.