Code 001136 Exhaust emissions - Adjustment screw fell out. I can cap it off or do I need a mixture?

I'm sure you already tried adjusting the fuel/air mixture screw or screws. Look at the adjustment screws again, is there a plastic cap on the screw? The cap will have a slot for a screw driver. Look at the cap closely is there a tab that limits the adjustment of the screw? If there's a tab limiting how far you can turn the adjustment carefully pry or pull the plastic cap off. Be careful you don't want to bend the adjustment screw. Under the cap you should find a slot in the actual head of the adjustment screw. Turn the screw about a 1/2 turn counter clockwise then start the saw and let it warm up. Once the saw is warmed to running temp adjust the screws slowly a little at a time until your saw runs at normal idle speed by itself. I was amazed after I did this with my saw. Once my saw is warmed up I can set it down and it will idle until it runs out of gas. You may have to play with the adjustments to get it where you like. Basically the plastic caps on the air/fuel mixture screws are an EPA thing to reduce emissions, in other words keep the engine running as lean as possible. Running to lean causes stalling and since 2 cycle engines are lubricated by the oil in the gas to lean can wear the engine.

The mixture screw is located in a resessed hole just above the therma start plate at the rear of the carby. The rear of the carby faces away from the inlet manifold and you require a special tool to access this adjustment. The other screw adjustments on the carby and linkages are for idle, fast idle, and choke limits including those models with automatic (thermal type) choke mechanisms.
I would advise that if you make any adjustments to the mixture that you have the mixture checked using an exhaust gas analyser.However, as a general rule of thumb, screw the mixture adjustment all the way in until you feel it tighten but DO NOT FORCE IT !! the screw has a delicate needle valve on the end which will be damaged if the screw is forced beyond it's normal length of travel.
Unscrew the mixture screw a total of one and a quarter turns back out and then have the setting checked with a exhaust gas analyser. Too rich and not only is this expensive but will cause damage to spark plugs etc. Too lean a setting will cause a misfire which will damage valves and pistons.

by adjusting the air mixture screws turning them out by quaurter turn at a time on the carbs but before you do that check to make sure your air filter isnt clogged because that can cause the same problem as well as poor fuel consumption
hope this helps

hi erdnaway

im dave hope i can help

technically the idle control on your vehicle is computer controlled and non adjustable. If the idle is high or low there is likely a code in your emission system (check engine light) and a sensor or emissions part that is not working properly or the computer itself. However if you look on throttle body you will find a slotted screw that will adjust the air/fuel mixture to get a better idle. When you find the screw be sure to have the engine running while you adjust it so you can hear the differences. If you would like to fix it properly you will need to the pull the codes from the computer diagnostic terminal. If you'd like to do that after adjustment of your air/fuel mixture post back. It would be a good idea to make a mark between the screw and the throttle body so that when you fix the emission related component causing the erratic idle you can put the screw back to its original position before restarting the engine