carb tuning for NOT lean

[daemon2525]

I have occasion to work on some chainsaws from time to time.

With so much talk on this board about lean seize, I thought I must address my tuning technique.

When a saw will not run. I'll put in a carb kit, and then turn the needles out 1 full turn. I adjust the low until it will idle well. Then on the high speed, I will keep opening it up until it will wind out really well.

Is it likely that I am now running too lean?

Should I be opening the high speed needle until it fails too rich and then come back down?

I think I know the answer and have read every post here for about a year.
I am however not able to understand the "4 cycling " that everyone is talking about.

thanks
Larry in Indiana

 

[skwerl]

Here you go:
http://www.madsens1.com/sawtune.htm

 

[Crofter]

If you open high speed way oout it will be blubbering rich at full throttle and clearly 4 stroking. Turning the HS screw in will cause it to start to clear up and as you continue leaning it, it will transition to screaming clear 2 stroke. That is too lean. Now open it up till it is just breaking back and forth between 2 and 4 stroking. A lot of useres on milling or big wood cutting will have it a bit closer to four stroking and it cleans up to 2 stroke under load. If the saw has a governor then this system does not work as the governor cutting out can still make a too lean saw sound rich. That is how I set up.

 

[davefr]

"As close to smooth as you can get while still in the rough"

 

[Lakeside53]

If you haven't messed with the muffler, and are unsure, just leave it out 1 turn... or whatever the Manf requires . Most carbs are 1 turn out (without limiter caps) but some are 2, 2.5 etc so you should check. The standard settings pretty much guarantees a slightly rich condition.