Dolmar 64xx/73xx/79xx series, smurfs and solo 665/675/681 thread

[huskihl]

I think you need to build another with a solo crank. And your piston options open up at 50mm. Gotta go after the mutt.

@Hedgerow

I like yer way of thinkin'

 

[Hedgerow]

Ppffftttttt.....

 

[Adirondackstihl]

Ppffftttttt.....

Sup Matt

 

[Hedgerow]

Sup Matt

SW MO's temp and humidity..

I hate August..

 

[Hedgerow]

I think you need to build another with a solo crank. And your piston options open up at 50mm. Gotta go after the mutt.

@Hedgerow

Hey..
Don't you have a new 5105 to build?

 

[Miller Mod Saws]

Hey..
Don't you have a new 5105 to build?

Actually have 6 on the way. Lol.

 

[huskyboy]

Let’s discuss timing advance next on this series. I advanced the timing .025 off key or roughly 6 degrees (which I heard these liked). Seemed to respond well in the small test log I had. Will get it in some larger wood soon and will share my findings... So to advance or to not advance? What coils respond well and what ones don’t? What advance do people like on 272 unlimited coil? I know Kevin mentioned earlier they start kicking around 38 degrees or so. Let’s hear some more .

 

[Backtroller]

Mine is advance about 1/3 of the key. Revs quick. Far far quicker than it had been.

 

[T.Roller]

Well I just got mine together after porting it. I haven't advanced the timing yet. I'll run a tank or so thru it then advance the timing and see what happens

 

[huskyboy]

Well I just got mine together after porting it. I haven't advanced the timing yet. I'll run a tank or so thru it then advance the timing and see what happens

I like doing mods in steps, makes sense to me to see the gains bit by bit.

 

[Hedgerow]

Timing advance ALWAYS helps...

Take it for what it’s worth.

 

[dustinwilt68]

I agree, lets you feel where the gains really came from

 

[Miller Mod Saws]

If you don’t have a degree wheel. Put a line from your jug to your flywheel. Then put another line 5 mm to the left. And advance it that much. 5mm of movement is roughly 6 deg.

 

[Poleman]

I like between 30-33 degrees with the 272 coil. I find each saw and the porting it has can make a slight difference in the way the particular saw runs, thus the slight difference.
Advancing really helps throttle response. The 30-33 degrees seems to work well and not to much for starting also.
Stock about 1/3 of the key width.

 

[David Young]

If you don’t have a degree wheel. Put a line from your jug to your flywheel. Then put another line 5 mm to the left. And advance it that much. 5mm of movement is roughly 6 deg.

what is the diameter of the flywheel?

 

[Adirondackstihl]

what is the diameter of the flywheel?

Yep
Based on a 7” dia.....5mm only gives about 3.25 degrees

In order for 5mm to equal 6 degrees, the flywheel would need to be 3.75” diameter

 

[Adirondackstihl]

Based off 7” dia......

 

[David Young]

I think it is around 5.5-6 " probably something metric.
roughly 1/4" puts you in the range which would be like 6mm

 

[Adirondackstihl]

Based on 6” dia 5mm = 3.75 degrees (roughly)
Based on 5” dia 5mm = 4.5 degrees (roughly)

 

[Adirondackstihl]

I think it is around 5.5-6 " probably something metric.
roughly 1/4" puts you in the range which would be like 6mm

@ 6” Dia, 8mm (0.315”) will give 6 degrees