Swapping spark plug boots(and other messed up ignition stuff)

[keatonx]

Hi. I'm building a weed eater bike and I jst spent half the day trying to start my stupid 31cc MTD engine. It has a crappy coil that only sparks if you pull the starter really fast, so I was swapping coils from a million other engines. The best coil (which was rusty, but who cares! it works!) didn't work properly. It ran extremely retarded, even though I had it at the most advanced position. It also go really hot in a bout 30 seconds of running! So I chose to go back to my other coil. It wasn't starting, AT ALL, till it rumbled, shocked me from the housing, then quit. After getting real frustated, as I need this engine for a science fair, I checked out the boot and found out he problem. This engine had the spark plug facing down, so I was pulling this engine with all it's weight (+ my leg) on the spark plug boot. It had been shoved all the way on to the plug, and part of the coily thingy in the boot tore through the rubber, which probaby grounded to the wet snowy metal grate I was standing on, shocked me, and killed the engine. Since I have tons of old coils, can I get the rubber part of the boot off one of those and put it on this wire? Does anybody Know why the rusty coil acted retarded? It makes way better spark than my other one that came with my engine!

 

[Dave C]

All you can do is try. See if you can get the whole plugwire intact off one you don't care about and install that. If it's not molded in I'll bet it unscrews from the coil just like the Chinese one.

The Chinese one is made in a toy factory from 6 different pieces. A real sparkplug wire is 3 piece.
Pretty stupid if you ask me

 

[keatonx]

These coils have the plug wire molded into them with that hard, shiny black stuff they fill ignition coils with. The wire won't budge, but can I pull the boot of it's wire and keep the coily wire in it intact?

 

[ibdennyak]

You should be able to pull the boot off and replace it with a new one. I used to put a new end on the plug wires along with a boot. Cut the insulation off with a utility knife leaving about 1/2 inch of wire (or conductor if it is the carbon stranded), fold the conductor around, and crimp on a new end. Might still be available at a small engine shop, or Napa etc. A shot of WD40 aids in sliding the new boot on.

 

[keatonx]

I pulled the boot off another engine and the metal coily thing stayed on the wire. But the broken boot seemed glued on on to the wire so I had to cut it off. but I got the new boot on fine.

 

[ibdennyak]

Cool, do you have spark now?

 

[keatonx]

Yup, still not perfect , but much better than before. I gave the coil thing better connection to the wire than before.