Stihl 031av chainsaw not starting

[BryceDxx]

I found an 031av chainsaw in the trash a couple years ago, points and condenser needed replaced, so I replaced it with an electronic spark chip about a year ago. Also cleaned carb, and I got it to start, but wouldn’t idle well, but revved up quick and loud, had a great sound. I didn’t have a chain for it at the time, nor any trees to cut at the time, so it has sat in my garage, empty of gas as well.

So I have a chain now, and I put about year old gas in, and it started for a couple seconds, and I had to keepit throttled for it to stay running, but it would run poor and die fairly quick anyways. I got it to run a couple short times, and then now I can’t get it started.
I know now, my gas was pretty old, and bought new gas and mixed it fresh today. Also cleaned the carb, though it looked very clean already, and noticed that one of the rubber gaskets is warping or shrinking, I put it back together anyways and tried running it with new gas and can’t get it running.

Air filter and spark plug is brand new, Rubber air intake isn’t cracked or leaking, fuel line is good. Also impulse fuel pump line, I think is what it’s called, isn’t leaking or cracked, not clogged either.

I’m thinking of buying a cheap 15$ knockoff carb from eBay was wondering if anyone had any advice

 

[North by Northwest]

Hey bud , under the diaphragm on Stihl saws are a inlet needle valve that allows fuel when diapham impulses from the crankcase are created. This valve is covered by a very small 2H pencil eraser size screen , which is a cheap form of prefilter . It often become a fouled with efuel gum or dirt/debris . If so erratic idle poor starting or no run can be experienced. If you have quick start , I prefer carb cleaner then spray some into the carb or spark plug hole . If it pops or farts its carb related . I assume you already checked for good spark ? Also fresh fuel mix with some concentrated carb cleaner (2 oz) added will eventually clean up any residual internal gum . Again i assume you have already removed the h& l speed jets and spray or tag wired them out. My bet is the inlet needle valve fouled as 1st advised . In the future post in the chainsaw forum for quicker response . P.S. The iffy looking gasket or diaphragm may need replacement at later date to ensure proper idle condition , also mix gas & oil @ 50:1 ratio .. Cheers !

 

[grizz55chev]

I found an 031av chainsaw in the trash a couple years ago, points and condenser needed replaced, so I replaced it with an electronic spark chip about a year ago. Also cleaned carb, and I got it to start, but wouldn’t idle well, but revved up quick and loud, had a great sound. I didn’t have a chain for it at the time, nor any trees to cut at the time, so it has sat in my garage, empty of gas as well.

So I have a chain now, and I put about year old gas in, and it started for a couple seconds, and I had to keepit throttled for it to stay running, but it would run poor and die fairly quick anyways. I got it to run a couple short times, and then now I can’t get it started.
I know now, my gas was pretty old, and bought new gas and mixed it fresh today. Also cleaned the carb, though it looked very clean already, and noticed that one of the rubber gaskets is warping or shrinking, I put it back together anyways and tried running it with new gas and can’t get it running.

Air filter and spark plug is brand new, Rubber air intake isn’t cracked or leaking, fuel line is good. Also impulse fuel pump line, I think is what it’s called, isn’t leaking or cracked, not clogged either.

I’m thinking of buying a cheap 15$ knockoff carb from eBay was wondering if anyone had any advice

Have you removed the muffler to inspect the piston condition? If not, that’s a good place to start.