I need to know the starting point and how may turns to adjust the high/low speed carb screws. I have the tool. but no in fo.

May be plugged carb but often this is high speed and low speed carb adjustment. Requires special tool to fit adjustment screw...i always take the carb off and use dremel to cut these two air mixture screws....cut a slot on the top turning them into a slotted screw, then open each one counterclockwise 1/4 turn when carb is reinstalled. Run it and make adjustments two low and high speed screws till it idles nice and throttles up smooth and quick.

You will need a special tool to adjust the anti tamper screws, do not adjust them to over come some underlying problem i.e dirty fuel, blocked air filter or dirty or blocked air filter. if the screws have not been touched this will be a good starting point, both screws are fuel screws so unscrewing will increase and richen the mixture,
Always start with the L screw first, with the engine running gently screw the adjuster in leaning the mixture, the engine rpm will start to increase, at the point where the engine then starts to die unscrew the adjuster about 10 minutes on a clock face, the H screw will control the high rpm, with the trimmer cord pulled out to the correct length open the throttle fully, screw the adjuster slowly in or out to achieve the greatest maximum speed too far in it will die, too far out it will die, allow the engine to idle, snap the throttle open it should pick up without hesitation, if not turn the L screw our slightly to increase the fuel supply.

Set both the high and low mixture settings two full turns back from the closed setting(full clockwise).. Set idle speed for all ahead full.

Start sucker and after a warmup throttle it down and then start adjusting the low mixture screw for fastest idle. Then lower idle some more but not to point where it starts to run rough. Then rev the sucker to high speed and adjust the high mixture for max speed. You may have to make a slight adjustment on the high speed to get a smooth transition from low speed to high.

Hi Mr. Martin:
Not quite sure what kind of adjustments you want to do.
All the chain saws that I've experience with have two slotted screws, one high speed, and one low speed. There may also be an idle stop adjustment screw.
Adjustments typically consist of:
1) with the saw running, adjust the low speed screw so that the engine is running smoothly.
2) with the engine running, increase throttle to maximum rpm and then adjust high speed by leaning (screw in) until maximum rpm starts to drop off, then back out 1/3 turn.
3) let the saw return to idle rpm. should be smooth, and chain not turning. Adjust as necessary.
Tool required is small screw driver. It can help if you put a small piece of plastic hose over the blade so that it will not slip off the head of the screws.
Cheerfuls

start by turning adjustment screws in. turn low speed out one turn and the high side 3/4 turn. start engine and adjust accordingly. the one turn and 3/4 turn are the starting point. saw should start at these settings and then you can fine tune. without knowing your elevation I can't give you the number of turns .

1.5 out each usually... Try it around there I guess

Hi montex124, I will try to help. In the past few years carb makers have been making changes. Some carbs have no adjustment at all, the ports are all fixed inside the carb. Other carbs have only the idle speed mixture screw that can be adjusted, like yours seems to have. Is this screw you mention at the top and completely outside of the carb to adjust the throttle? If it is it's probably the idle speed screw which can be adjusted to any idle speed you want and has nothing to do with the air fuel mixture but If it is right next to the idle mixture screw, it might be the high speed mixture screw but is capped so it can't be adjusted. The low and high speed mixture screws should be marked next to each screw H and L.
The 1 1/2 turns suggested is sometimes just right but other times has to be adjusted, so you can try adjusting it to get your idle but maybe adjust the idle speed screw first to get a higher RPM so it doesn't stall on you. Like I said earlier it just adjusts the throttle, and is like when you are using it, and giving it gas as they say. I hope this helps just a bit. Regards and good luck. Get back to me if you need more help or just let me know how you did. Denis.

Regarding the adjustment procedure you generally start your low and high mixture screws at one turn from seat, or slowly turn them in all the way until they bottom out and then back them out one full turn. You will adjust the high speed mixture screw at full throttle and get the median point between too rich (loads up) and too lean (dies out). You will want to do the same thing with the idle mixture screw, just adjust at idle rpm. You will also adjust the low idle mixture screw to give you a smooth transition from idle to throttle up. Once this is obtained, you adjust the third or idle speed screw low enough so the chain does not turn at idle rpm but high enough so the saw doesn't cut off. Hope this gets you going.

ther is no set setting but to get it to run so it can be adjusted. lightly close the high off then open the low about two turns. try to start if starts slowly adust the low screw till it runs normal with the choke all the way off. then start to add throttle while turning the high out till regiured rpms ar reached with no misses. this takes awhile even fo a seasoned mech and may require several attempts

if its the carb screws your talking about
one it for fule mixture the other is for air,,,
air for tickover fule mixture for rev's
if its running well leave them be?