QuestionHi John,
I have 2 problem string trimmers. I got both of them used, cleaned them up and tried to get them running right, so I don't know their history before me.
1. McCullogh (sp?) trimmer: I had to drain and replace fuel to get this one going. It took a while, but I finally got it to start easily; however, it will not rev up above ~1/3 max speed. The trigger and throttle plate move fine. If I try to throttle up too quickly, it will bog down and die. If I slowly increase throttle, it just won't go any faster, and the sound changes with the throttle wide open (sound through the carb). Oh, I doubt that it has anything to do with it, but I accidentally broke the original spark plug, and used a plug from the Toro trimmer below. It is a different model plug, but I can't see that affecting the engine in this way, especially so dramatically.
2. Toro trimmer: Loud noise like marble(s) shaken in tin can. I can't tell from where it's coming. I disassembled this to clean it before trying to start it. When I removed the carburetor, there was a big opening into the crankcase below the piston (lower piston and complete rod visible). I didn't see anything amiss, though I wasn't specifically looking for anything since I didn't know about the noise then. The spark plug is OK, and I have seen no other evidence of a foreign body in the piston cylinder.
Thanks in advance,
Scotty
Answer Hello Scotty:
Trimmer #1- Remove the Muffler and Check the Exhaust Port for Blockage. Check the Muffler and the Spark Arrestor Screen for Blockage Also. The Spark Arrestor Screen is in the Muffler. Set the Plug Gap to .035in. Trimmer #2- Check the Muffler. Check the Clutch. Carbon that is Loose in the Muffler will Sound like Marbles. The Clutch Bearings Bad will Sound like Marbles. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.
Good Luck
Respectfully
John
