ol'homey
ArboristSite Operative
Last Oct I ran all the gas out of my little Echo trimmer and put it away. Tried to start it today and it would barely idle, bog on acceleration, and run lean and cut off at WOT. The H mix screw had no effect. Pulled needle out shot carb cleaner in, no joy. Pulled the metering diaphragm off and shot carb cleaner through both the H and L circuits, both were clear. The metering diaphragm looked fine, soft and pliable. I put a GND-12 (fits the Zama C1U carbs) kit in it 2 yrs ago so I expected it to be fine. Pressure tested the needle valve, checked out fine. Checked metering lever height, was level with the carb body gasket surface which was fine. Put it all back together, no joy. Took carb off again. This time I took off the fuel pump diaphragm cover. First thing I noticed was both of the little flapper valves were all curled up and not even covering the holes. I've never seen them all curled up like that before. I remembered that the kit that I got had 2 fuel pump diaphragms in it. One was made of the same material as the metering diaphragm which is the one I used (and today found curled up). The other was made of some kind of thin plastic (mylar?). Luckily I found the plastic pump diaphragm still sitting in the bag the kit came in a box under my work bench. Installed the new diaphragm and the little Echo trimmer runs like a champ again! Questions:
1. What caused the flappers to curl up like that? Was it the 10% ethanol?
2. Did Zama update the material used in the fuel pump diaphragm to plastic to better resist ethanol?
3. Is this problem (curled flappers) unique to the C1U Zama carbs or have you seen it in other (ie. chainsaw) carbs? How common is this problem? Thanks, Lee
1. What caused the flappers to curl up like that? Was it the 10% ethanol?
2. Did Zama update the material used in the fuel pump diaphragm to plastic to better resist ethanol?
3. Is this problem (curled flappers) unique to the C1U Zama carbs or have you seen it in other (ie. chainsaw) carbs? How common is this problem? Thanks, Lee