I'm having a problem with my MS250. It has always run great, but about 2 weeks ago it started where it doesn't want to stay running at idle. I have to milk the throttle to keep it running and sometimes it still stalls. It seems to run ok at wide open, but i have to blip or milk it to get it up to full throttle. I have some firewooding to do tomorrow and kinda need it so any advice would be appreciated. I got in at dark tonight and have not looked it over at all yet other than taking the cover off and wiping some dust off the air cleaner. It does smell rich when it stalls out, so i'm definitely going to service the air cleaner and pull the plug to see where I'm at there. Also, it does seem to run worse on it's side. I definitely have to get it up to WOT before even thinking about turning it on it's side. Thanks!
If cleaning the filter doesn't help. Clean the carb good and replace the fuel line to start with. Steve
Quote from: thechknhwk on September 22, 2012, 10:21:27 PM
........ Also, it does seem to run worse on it's side. .........
This is an indication of a jet valve issue. Leaning out of fuel due to air intrusion into the metering chamber.
But.
Quote from: thechknhwk on September 22, 2012, 10:21:27 PM............. It does smell rich when it stalls out, ...............
contradicts that because you are getting too much of fuel
Pressure test the carburetor to check whether the inlet needle is leaking.
Joe
Thanks for the insight guys. I don't know how to pressure test the carb. I guess I'll have to look that one up.... if it requires any special tools I don't have them.
Just take it apart and clean it first. I've never pressure tested one yet . Steve
Quote from: thechknhwk on September 23, 2012, 09:06:54 AM
I don't know how to pressure test the carb. I guess I'll have to look that one up.... if it requires any special tools I don't have them.
You've the stuff they use to check blood pressure?
The rubber bulb with the tubing and stuff?
Okay, you dont need the 'stuff', only the bulb and tubing.Either from an old apparatus or from a shop that sells medical supplies.
Here it cost less than a dollar.
Once you have one, open the top cover of the carburetor, the end with 2 screws
Once you have the lid off carefully remove the diaphragm and gasket underneath.
Now, connect the tube of the pressure bulb to the metal tubing to which the fuel hose is usually connected.
Drop the carb into a beaker or can with fuel or kerosene or even diesel.
Press the bulb a couple of times.
Are there any bubbles formed in the beaker.
If yes, check where they are coming from.
Joe
Good information, and thanks.
Ended up being pretty simple. I took the air cleaner off and vacuumed it off with the shop vac. The intake was a little dirty, so I flipped the saw upside down and sprayed carb cleaner in it wiped it out, put it all back together and it's running like a champ again.
I got about 3 face cords down and cut, 1 of them split, now to pick up the rest after lunch.
On the job i'd pop the air filter off, using carb cleaner or starting fluid, spray from inside out, wave in air on till dry, put back on.
At home i'd clean with soap an water [i used Thrill dish soap] let dry over night.
I ran a Stihl 034 3 yrs 5-6 days a week, never had the spark plug out of it. The crank bearings started making noise, traded for a new one. [ never had to replaced the rewind rope ]