Stihl 440 starting problems

Allboy · November 12, 2013, 10:41:20 PM

I'm a newbie and this is my first post here. Hopfully someone can troubleshoot this problem. My MS440 would not start. So i pulled the plug and added some fuel to the cylinder. I started and ran well. It restarted all day when warm, but once it cooled down it wouldnt start. Can anyone suggest what this might be? Carburetor maybe?

I use this saw for hunting and only use it once a year. I had fuel in it but I had put stableizer in it. Is it best to store the saw with no fuel if it sits unused this long?

Allboy · November 13, 2013, 05:31:55 PM

Not sure if it matters but my saw is a 440 with the newer fuel/bar oil caps.

ZeroJunk · November 13, 2013, 05:37:00 PM

I would take the air filter off and check to make sure the choke is actually closing when you put the control in the start position. Linkage can get bent. If the saw runs good and will sit and idle for a while it should start.

Allboy · November 13, 2013, 05:51:49 PM

I checked the choke and it was fully closed when switched to choke position.

Andyshine77 · November 13, 2013, 06:15:13 PM

How does the saw accelerate? does it stumble off idle? What is your starting procedure?

On a cold saw set to full choke, pull until it pops or stumbles. Now flip the switch up one notch to high idle, pull until she runs. If you miss the initial fire with the choke still on and you keep pulling, you'll flood the saw. I see this happen regularly.

You should never store anything with fuel still in the tank, with or without a fuel stabilizer. Drain the tank and let the engine idle until it stops running, this removes the fuel from the carb. Fuel related issues, are the number one problem people have with handheld OPE.

redfin · November 13, 2013, 06:23:20 PM

I recently rehabed an 026. The saw did somewhat close to what you said until I replaced the diphram in the carb. The only thing could figure is I could not get enough vacuum just by pull starting it but will the saw running the daiphram worked ok?

I am in no way saying this is your trouble just have had similar troubles.

Al_Smith · November 13, 2013, 06:32:58 PM

The carb innards get stiff .They don't work as well .Just rebuild the carb which is no big deal and most likely that will cure it .

Andyshine77 · November 13, 2013, 06:33:51 PM

Quote from: redfin on November 13, 2013, 06:23:20 PM
I recently rehabed an 026. The saw did somewhat close to what you said until I replaced the diphram in the carb. The only thing could figure is I could not get enough vacuum just by pull starting it but will the saw running the daiphram worked ok?

I am in no way saying this is your trouble just have had similar troubles.

The ethanol in today's fuel is hard on carb diaphragms, they get stiff and stop pumping and metering fuel properly. Running a saw with bad carb diaphragms is not a good idea, it can lead to lean fuel conditions.

Allboy · November 13, 2013, 06:35:41 PM

I use the normal Stihl starting procedure. I have put some time on the saw so I know something is broken and its not a choke or starting procedure. I guess I should start with a carb rebuild kit and see what happens.

Andyshine77 · November 13, 2013, 10:53:46 PM

Quote from: Allboy on November 13, 2013, 06:35:41 PM
I use the normal Stihl starting procedure. I have put some time on the saw so I know something is broken and its not a choke or starting procedure. I guess I should start with a carb rebuild kit and see what happens.

That is where I'd start!! If you didn't leave fuel in her you'd likely be good to go.