Small Engines (Lawn Mowers, etc.): lawnmower, briggs and stratton, gas lawnmower

Question
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Hi Michael,

I've checked the mower and there is no spark so I will have to get a new spark plug.  Is that normal for a mower that has been used less than a dozen times?

Thanks,

Lisa

Followup To
Question -
Hi Michael,

I bought a gas lawnmower last summer with a 3.5hp Briggs and Stratton motor.  We had trouble starting it off and on, and it wasn't used much last summer, but now I can't get it to start at all.  Any ideas?

Thanks,

Lisa
Answer -
Hi Lisa,

You will need to determine if the problem is a lack of spark or a lack of fuel flow.  Remove the spark plug, reconnect the wire and lay it against the engine head.  Pull the engine over and watch for spark at the plug's electrode.  If you have spark, try squirting fuel or starting fluid into the carb intake while trying to start.  If it runs with fuel added, then there is most likely dirt, debris or gummed fuel inside the carb.  The carb will need to be removed, disassembled and all the small internal openings cleaned.  

Let me know how you make out.
Michael  

Answer
Hi Lisa,

You could try another spark plug (It's good to have a spare and they are usually replaced each year.) but even a bad plug is rarely are the cause of no spark.  (A bad spark plug may have weak spark or not have proper spark under compression but usually will always spark.)  Before looking for the cause elsewhere, make sure that the plug was making good, firm, grounding contact with the engine and that the safety lever is depressed.  This test is easier with 2 people.  If still no spark, I would check the safety kill switch.  It is usually located under the recoil/cooling shroud.  Trace the linkage from the lever on the handle, to the switch.  If that is okay, then the ignition coil may be bad.  The coil is under the flywheel and would require experience and a special tool to replace.

Keep me posted.
Michael