Shaun,
The start settings, meaning the settings that are the most common settings as a base point so you can get the saw running and then adjust it from there are at the end. Lets see if we can tune it out. I am not sure how new the mac 436 is but if it is an older one over 6 years or so or newer than 2 years old your carb should have 3 screws on it. Two of them are side by side of each other with single letters H and L. The other one is a larger screw and this sets your idle speed. Open up the cover to the carb and look to see if the tip of the larger screw is touching a cam type thing. If it is not then this could be the problem. Start by turning the idle screw in until it touches and then turn 1/4 turn. Keep doing this for about 2 full turns. If this doesn't help then you have a mixture problem. Back the idle screw out just until it touches and then turn in 1/2 turn and leave it. If you have the air filter off make sure your in a fairly clean area and start the saw and warm it up. Once it is warmed up let it come down to an idle and just before it starts to die start to place your finger over the carb. intake. Shouldn't take much. If the starts to run better then your mixture on the L screw is too lean. Turn the L screw out about a half turn. Keep doing this for about 2 full turns. If it still won't idle you will probably need a carb. rebuild. Now if the saw runs WORSE then turn the L Screw in 1/4 turn at a time until it starts to run on its own. Once you get it to where it runs pretty good by using the L screw and Idle screw you will have to re-adjust your fast idle. Now to know that your settings are correct for the low speed settings from an idle you should be able to pull trigger and the saw should snap up to speed. If it dies then you need to back the L screw out until it snaps up. NOW it may die coming down to the idle. If this happens then turn your idle screw it a bit. Once you have it to where it idles and snaps up to speed you can now fine tune the fast idle. You may want to use hearing protection for this. Start the saw and be ready to turn the H screw. once the saw is at full throttle turn the H screw IN until it starts to bog down and then back it out until it start to bog down. Now turn it in slowly until the speed picks up to a smooth speed.
Your base settings to get ANY 2 stroke running on the H and L screws is 1.5 turns OUT. Turn screws in just until they stop. Then turn out 1.5 turns. I will check back to see if you have posting on this listing again. Let me know if you have any problems. please forgive spelling errors. it is late and I can't sleep.
Luggnutt
February 2012