Small Engine Repair.

I have no idea how to fix small engines. But I got a couple of suggestions from friends of things to try, so here they are for you. If the thing won't start and it's been sitting around a long time:
  • It won't start without a spark.
    Pull the plug, reconnect the plug to the wire and lay it on its side against the motor body, pull the starter rope, and ...
    if there is spark, then that's good. If not, then it's bad, so...:
    • Replace the spark plug and try again. Or...
    • check the magneto and wiring to the spark plug in case something is disconnected.

  • It won't start without fuel.
    • Is there any gas in there? Take a look. Add some.
    • Is the gas in there old? Old gas doesn't run as well, often gums things up, often won't run at all. Yes, really. Ethanol evaporates quickly from the blend so use new gas. Drain out the old, pour in some new, and use some spray solution to degum it, shooting into the carburetor inlet.
    • Is it a two-stroke engine? If so it needs gas mixed with two stroke oil, typically at a 1:40 ratio.

  • It won't start without air, remove the spark plug and pull the starter rope. You can put your finger on the spark plug hole and feel air moving in and out. Of course that doesn't help you since the air might not be coming in through the valves when the spark plug hole is open.

  • It won't run well without the right air/fuel mixture. (My brand new motor came with Cal EPA adjustments and zooms then dies immediately...) It needs the carb adjusted properly, like this.
    • Turn the idle screw down till it barely dies, then turn it back a quarter turn.
    • Turn the low speed screw one way till it stalls, then the other way till it stalls, then put it halfway in between.
    • Turn the high speed screw one way till it stalls, then the other way till it stalls, then put it halfway in between, then make it a little (a quarter turn) richer.

  • If it still doesn't start, I have no idea. If you figure it out, let me know and I'll share it here. Thanks!

Copyright © 2000-2011, Thomas C. Veatch. All rights reserved.
Modified: March 31, 2011; August 11, 2012