Frustrated with a Cub LT 1018 No Start problem

[Rookiesmom]

Thanks fellas,
I had to interrupt this repair to have repair work done on my elbow (Ulner nerve decompression). Elbow is doing well, albeit with a fistful of stitches. Hopped back on this mower again today. Took both plugs out put non-connected spark plugs in the top of the cylinders and checked the spark off of each each original spark plug by grounding them against the frame and engaging the starter as suggested. Both have great spark, no issue there. Engine spins well, just won't fire and run. Tried a squirt of starting fluid down the carb intake, no joy. So noted the remark above about the 12 gauge but this isn't my mower and while it is generally reflective of my frustration, it would be a waste of 3 good slugs. If it was electrical we would not have spark nor would the starter turn the engine. Both of those things are there. Steering bushing really isn't much in the way of electrical connectors and the engine spins so, I have to set that aside. Back to fuel? Any last zebras we haven't checked? I even stuck a small magnet down the oil tube and waved it around to find little attached to the magnet. I may just have to swallow my pride and take it to the cub guys. That hurts my pride/and pocketbook the most. Especially if it turns out to be something stupid simple.

 

[biggertv]

About the only thing left is Timing. Since the key sheared at least once that we know of, the crank or flywheel or both could be damaged. Remove the Flywheel just one more time and inspect. I once installed a roll pin on a damaged crank and flywheel. It works, and will never shear a key again.

 

[slomo]

Both have great spark, no issue there.

A plug firing in air is way different that under compression. You need more spark energy under compression.

Take a simple 12 volt DC test light. Ground the test light clip to the engine on BARE METAL. Now the pointed end shove it into the plug boot CONNECTOR. Crank the engine without ALL plugs so the starter will spin faster/easier. Move the pointed test light end AWAY from the plug boot. Look or MEASURE how far the spark can jump. Need at least 0.25" or more preferably to light the plugs.

Also recommend non resistor plugs in all small engines. Those coils have weak azz spark compared to cars and trucks. Champion plugs will cross over to non resistors. NGK my favs are mostly resistor plugs.

Check for spark under low light or night time conditions. This is a must to see the spark in a more noiseless condition. Noise is meant was the lack of say direct sunlight overpowering the spark color and length.