Spark plug cable question
 

OK no one la ugh, I have a Dle 30 and the spark plug lead has a metal outer,this outer chaffed thru on the cowling exposing the inner cable. It still had spark but was causing a problem with spark jumping across from the inner to the outer covering. Even with the outer metal covering off the plug still sparked leading me to think that this outer metal covering is just for protection. However the cdi while I was still testing stoped producing spark. I replaced the cdi(it comes with a plug cable that cannot be removed) However still no spark. I then relplaced the pick up and it sparked fine. I then fidded the old cdi to test if it was working with the new pick up cable. it produced a spark even though the outer metal covering of the lead was in two peaces. I was still checking it out ( let it spark about ten times) when it went dead. I tried the new cdi and found it also now dead. It seems that the new pic up burnt out as well, when I fitted it to the cdi with the broken outer cable. What purpose does this metal covering on the spark cable serve,and is it possible that tha fact that it is in two that the cdi burns out the pic up?

RE: Spark plug cable question
 

The metal braid that covers the HT lead from the module to the spark plug cap provides shielding to guard against ignition induced RF noise, and once broken must be repaired/replaced if possible. If for any reason you attempted to spark the ignition without the plug firmly in place in the cap and grounded against the cylinder it is very possible that you might have damaged the ignition.

Karol

RE: Spark plug cable question
 

Also the metal shielding is the ground for the ignition. So if the shielding is completely separated there is not ground to the plug

RE: Spark plug cable question
 

And the spark goes through to ground at the sensor...Goodbye sensor...Right away in most cases...

RE: Spark plug cable question
 

Ah hah ! as i thought. So we learn, do you think it would be possible to fix the outer by joining some heavy duty braid across the gap?

RE: Spark plug cable question
 

The moral of this story is protect thy sparkplug cable from damage lest thy sensor go poof! (or something like that!)

Seriously, use some type of protective covering on the plug lead .... I prefer plastic split tubing or small foam rubber pipe covering ...... plastic spiral wrap is also popular. Most important is to route the cable well away from anything that can damage it ... especially the exhaust system and sharp cowl edges. Cut the cowl enough to well clear the cable. If the cable rubs on anything, it will be damaged in time.

RE: Spark plug cable question
 

If the inside rubber is cut at all it will probably leak spark to the outer...RC EXLs make lots of spark...

RE: Spark plug cable question
 

It probably will work initially but long-term wise is not reliable due to engine vibration and oxidization. Soldering probably is difficult because the inner cable is just nearby.

RE: Spark plug cable question
 

It will probably not work. The cable isolation has a lot higher resistance than air, so inside the repaired cable the spark will jump right to the cable shielding. Maube filling the gap with acid free silicone before repairing the braided shield will do. Maybe.

RE: Spark plug cable question
 

Going to try something otherwise I will have to replace the cdi because the cable cannot be replaced. The cdi aint cheap!

RE: Spark plug cable question
 

If the damaged metal braid outer is close to the spark plug cap, you could cut the cable at the place and reinstall the cap there. I have never done it myself but knew DA has done it for me to replace the cap.

RE: Spark plug cable question
 

Neither is your model.

Karol

RE: Spark plug cable question
 

I agree