timing and the flywheel.... learn me please... FIXED pg 3

[Mattyo]

Ok, is there a guide somewhere that gives symptoms of what happens when a flywheel is advanced too much or retarded too much? ie, 10 deg back and you get boggyness or 15 deg foward and no power in the cut or whatever. .... anyone point me in the right direction?

build a 372 today, comp is ok, port work was ok, it 4 strokes at high rpm, cuts ok... but just a bit piggish. just doesn't have the zip that other 372's i've put together have... the flywheel is AM and actually requires a flywheel key. put a piece of romex in there, and torqued it down. just not sure if I advanced it or retarded it or what. would be nice to have a guide...what happens 5 deg forward or back etc. thanks

 

[PartnerR16]

Ok, is there a guide somewhere that gives symptoms of what happens when a flywheel is advanced too much or retarded too much? ie, 10 deg back and you get boggyness or 15 deg foward and no power in the cut or whatever. .... anyone point me in the right direction?

build a 372 today, comp is ok, port work was ok, it 4 strokes at high rpm, cuts ok... but just a bit piggish. just doesn't have the zip that other 372's i've put together have... the flywheel is AM and actually requires a flywheel key. put a piece of romex in there, and torqued it down. just not sure if I advanced it or retarded it or what. would be nice to have a guide...what happens 5 deg forward or back etc. thanks

To advance you rotate the flywheel counter clockwise. Not knowing the width of the keyway,you could try grinding down a penny or dime to moc a new keyway that'll advance the timing 3 to 4 degrees, this trick works well on Poulans. I'd stuff the empty area to retain the P or D in the desired position. Depending on compression will most likely limit the amount of advancement

 

[HuskStihl]

The AM wheel might also have weaker magnets and make less spark.
If'n it's sluggish, advance the wheel 3-4mm (basically 1mm equals 1 degree on a big husky wheel) and see if it perks up.

 

[HuskStihl]

Advance it too might and you might get a finger boo boo!

 

[Mattyo]

ok... see... I thought I advanced it ...at least a bit. the 14 awg romex makes a sloppy fit for a key. so I pushed it towards the advanced side... and torqued it. interesting about the magnets being weaker. hmm.

saw went out today to a job, he'll run it and see whats up.

if I had to guess it seems like its either too far retarded or the magnet's weak...interesting thoughts, thanks

 

[Mattyo]

of possible note, there seems to be quite a bit of unburnt fuel backspattering through the intake horn.. ..

 

[KG441c]

of possible note, there seems to be quite a bit of unburnt fuel backspattering through the intake horn.. ..

What did u take the intake floor down to?

 

[Mattyo]

100 120 80....nuthin crazy for a 372

 

[KG441c]

I know a symptom on a good bit of advance is yanking the starter handle out of your hand pretty quick

 

[Mattyo]

It's a new ngk plug...but am flywheel and coil.....

Nope...no yank...starts easy

 

[KG441c]

It's a new ngk plug...but am flywheel and coil.....

Nope...no yank...starts easy

Hmmm! 120 on the transfer is usually where u go ? Just curious , is there any freeport on the exhaust side?

 

[Mattyo]

I actually didn't touch the transfers...maybe they are closer to 121...

Don't know about free porting on exhaust side. ..sorry. ..

Case us decked 22 thousanths...to optimize squish

 

[KG441c]

Sounds like the only thing u changed was using the AM flywheel? Id advance that flywheel about .020 and try it again

 

[Mattyo]

Ya...it's a plan

 

[KG441c]

I did a 460 today and the factory keystock was .080 and I took it to .060 and torqued it. It yanked on the starter handle a tad but ran very good and throttle response was nice

 

[beaglebriar]

Pretty sure I have a OEM flywheel for a 385. I think they're the same as the 372. If you need it it's yours for the price of shipping. Consider it part of the Christmas giving thread. Just shoot me PM with your info.

 

[Big_Wood]

the 385 flywheel will bolt on and work but it is different. counter weights are heavier.

 

[beaglebriar]

the 385 flywheel will bolt on and work but it is different. counter weights are heavier.

That could be a good thing...

 

[Big_Wood]

That could be a good thing...

i've done it, i can't remember exactly how it worked but i think the saw lost some zippyness with bars under 28". i believe it pulled a 33" very well though.

 

[Gypo Logger]

i've done it, i can't remember exactly how it worked but i think the saw lost some zippyness with bars under 28". i believe it pulled a 33" very well though.

Zippyness?