Stihl 025 floods

[purdyite]

Working on this for a friend--it is clearly running too rich to the point that it slows and dies. Restarts with throttle held wide open--I adjusted the idle speed up and it still does it. I ran the carb through an ultrasonic cleaner. Carb only has low speed adjustment, and barely cracked open (less than 1/4 turn) it still dies. The only other adjustment I can think of is the metering lever under the diaphragm pump, but I checked with with the Walbro gauge. Also, would an aged, stiff diaphragm cause this? I can't think of anything else that would force too much fuel through besides the diaphragm and metering clearance or too rich low-speed setting. I'm open to any wise counsel out there. Thanks. (Or...do carburetors wear out?)

 

[Jasonrkba]

Id do a carb kit. If the diaphragm is stiff check the fuel and impulse line. I do all at the same time. Thats just a practice I've had success with. 025's are good little saws.

 

[Old2stroke]

Eliminate guesswork by pressure testing the fuel inlet to the carb, that will tell you if the problem is with the inlet valve not sealing due to dirty seat, a bad adjustment of the control lever or a stiff diaphragm that's stuck in a position that holds the valve open. Should hold 7-10 psi.

 

[purdyite]

Thanks for the replies...I pressure tested the inlet, would creep off of the 7 lbs. very slowly. I tried finding a carb kit locally, but ended up getting a new carb because no matter how I set the needle valve it would still back off so I figured it must be the seat that is bad or worn. I tested the new carb--it also won't hold the 7-10 lbs! So is it ok if it very slowly creeps down? The good news is that the replacement carb (Stihl OEM from a Stihl dealer) has a high-speed adjustment.

So where am I now? I will put the new carb on and see if it idles properly--will report back in a while.