My chain saw doesnt want to rev out until it is just about to run out of gas. Then it runs really good for about 2 seconds. I clean the air filter really well and it improves some, till it gets dirty again in about 5 mintues, but never as good as when it runs out of gas. How do I lean the mixture a little on these little pumper carbs? Is there anything in the exhaust I could do? Thanks.

 

adust the mixture screw

 

You are a bit rich on the jetting. Grab a small flat screwdriver and locate the carburetor. There will be two screws right next to each other. Those are the high and low speed jets. Fire up the saw and get it fully warmed up. Once it is completely warm, hold the throttle wide open and adjust the screws until you can get it to rev out all of the way. You may need to reset the idle after this is done.

 

Cool thanks, I just sorta figured this out on my own. I took the thing apart and have the carb in my hand (hope I can get it back together, lol). There are 2 screws like you said, but they dont have any screwdriver fittings on them, just some knurling on the sides (a 12-pt socket won't even fit it). They have an L and H next to them. So, I'm going to take a dremel and carve and slot in each one so I can use a flat screwdriver to adjust them. I'm guessing the H is the one I want to be adjusting? Do I back it off to lean it out? Or tighten it?

 

Thanks a lot for the advice. It screams now. I turned the H screw in a full turn after I carved slots in the tops. Didn't have to do anything else.

 

Well, can you fit your fingers in to adjust the screws? In should be leaner. Start with adjusting the high speed screw, just slowly turn it in and out untill you find the spot that it revs out the best. Then adjust the Low speed screw to get the best throttle response. Once you have the low speed dialed in, go back to the high speed and make sure the engine will rev out.

 

It wasn't that bad out of whack, its still new (time wise - old in terms of use though, lol). I just had to turn the H screw 1 turn and that was it.

 

What kind of saw is it?

 

poulan pro 46cc 20 inch I think (the one that is 2 inches longer than the rest). The $200 one from lowes. Its a decent saw, like the long blade, but it has cheap plastic parts all over that wear out. I went ahead n ordered plenty of chain tightening gears for it. Wore the 1st one out in a month. I've cut trees as long as the blade and it does the job.

 

Ahh, a pull-on. I've wrenched on some of those quite a few times, they do the job, but they are quite mickey-mousy. The nice new Stihls spoil ya.