carb adjustment

[high life man]

Hi,
I'm new to this forum, and glad to have found it. I've always thought that a chainsaw forum must exist somewhere.
It always takes me at least a tank of gas to adjust a saw carbeurator. When I'm done, my shoes are covered in bar oil, I reek of gas, and my neighbors are peering through the curtians at me. My saw dealer(50 miles away) can do it for me in about 90 seconds, and it always seems right on. The guy at the hardware store can do it, but it's never right and I wind up doing it myself anyway.
So, I need some help.


What I think I know: (correct me if I'm wrong)

1)You start by turning H, L, LA out 1 to 1.5 turns each from their seats.
2)If the saw bogs when you accelerate, then the L is too lean.
3)If the saw quits at idle, and oil drips from muffler, L is too rich.
4)Chain should barely creep when idle speed is adjusted correctly.
5)Set the H as rich as possible and still obtain steady rpm and smooth exhaust note at wide open.
6)If saw quits or has erratic RPM at wide open, H is too rich.
7)Strangely, I find it much easier to adjust a saw with a bad muffler.

Key things I would like to know:

1)Which is easiest to start with, H or L?
2)How do you know if H is too lean?
3)exactly how responive are those screws?
I usually adjust in increments of 1/8 turn.
4)Whatever else you think would help me.

Thanks in advance.

 

[tundraotto]

naww heere! get yarself one of them ravcounters - they do the trick from what i hear - twist the screws for the right revs and read you manual for which to twiggle first.

 

[Fish]

What model saw do you have? Do you constantly have to
adjust the carb? Daily? If so, you have a problem somewhere
that should be addressed before you burn the saw up. A saw
should when warmed up, be able to sit and idle until the fuel
is used up, if not, then something is amiss somewhere. Also at
idle, the chain should not move.
On adjustment, I warm up the saw, and while idling, turn the
L in until it starts to stall, then back off 1/8. The rpms rise at this point, so I adjust the the idle speed down until the chain stops.
The high speed is the bad one, adjusted too lean, you will have
the best, fastest cutting saw in the neighborhood for a few
minutes until the piston melts. So I advise you on that one to adjust it a little rich until you can set it with a tach.
Fish

 

[tony marks]

im gona print this for reference. thanks

 

[HUSKYMAN]

The saw should not sound smooth when the "H" adjustment is set either. When it sounds smooth you need to turn it slightly richer until it has a slight "burble" or "four stroke" sound to it. This way you know it is adjusted safely if you dont have a tach. I would have your dealer do it one more time for you and note how it sounds at wide open when you get it back from him. Fish is right, though, you shouldnt have to mess with it hardly at all. either the springs arent holding the screws in place or you may have a small air leak somewhere, and are trying to compensate for it. The carb may be gummed up, too

 

[davefr]

Go here (complete with WAV files!!):

http://www.madsens1.com/sawtune.htm

 

[tony marks]

thanks dave

 

[high life man]

Thanks a million, gentlemen!
The saw is an old 010AV that I picked up at auction.
I did find a leak in the fuel iline where it goes through the tank. I fiddled with it a little, and the hose broke apart in my hand. I replaced the hose and fuel filter, and I adjusted it with ease. Runs great now.
After a new sprocket, chain, fuel line, spark plug, oiler, and fuel filter, I could've added some pocket change for a new 009. Oh well.

 

[high life man]

Update:

I used the saw last weekend. Ran like crap. Ran good at home though after the fuel line. Brought it to the shop. They said new carb for $50. I kept the hard case it came with, the squared bar, new chain and new filler caps that will fit my 020, and my dealer traded me bumper spikes for my 044 along with a jug of bar oil in exchange for the powerhead.

I thought it would be a good saw for the rookies on the crew to run into the dirt and pinch in cuts. What a waste.

 

[high life man]

I almost forgot.

Thanks again for the help, guys. I printed out the adjustment info offered through the link. I learned a lesson, and am now proficient at carb adjustment.

 

[HUSKYMAN]

$5 says that saw had an air leak somewhere and no amount of adjusting would have got it right. Next try turning the saw upside down and sideways while idling to see if the idle changes. One of the sign of an airleak. Also you probably could have rebuilt the carb for $10

 

[wgr]

How does turning the saw reveal a air leak,does the fuel puddle on the leak and change the rpm.

 

[HUSKYMAN]

Walt can probably explain the mechanics of it better but I know it does work for some types of leaks. Also spraying WD40 behind the clutch on the crank seal can reveal a leak there also