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12iS Spark-Plug Wire Chafing

Bob Y

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When performing my 5-year coolant hose replacement, I had to unbolt the ignition coils to gain access. When I folded them back, I discovered the #4 cylinder top spark-plug wire had been rubbing on the air box and worn through the outer jacket and into the core. This was at 450 hrs. Five of the other12iS owners I know have discovered the same issue. My sixth friend had no signs of wear, but very close separation from the air box. So, six out of the seven of us had this issue. One found wear on the boot at the ignition module. The paint on the air box is slightly abrasive, so vibration and rubbing caused this. It’s hard to tell how long it would have been before ignition problems would have occurred, so I’d recommend all you 12iS owners to check for this. It’s very difficult to see without specifically looking for it because it’s so buried under the ignition modules.

Slipping tubing over the contact area will take care of minor abrasions. I added tubing in addition to replacing the wire. If you need to replace the wire, Lockwood sells it by the meter. The Rotax part number is 865 711. I’d be interested to hear from others that check for this problem to see how wide-spread it is. This is a Rotax issue, not a Van’s issue.
 

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I have had a major issue with ignition wire chaffing under and around the ignition coils on my 912 ULS. I did a write-up with pictures in this post.

Good catch on your chaffed wire but now keep looking! It is hard to inspect under and around the coils but worth it. Getting the assembly out is a little tough. A bore scope might give you a good first look in that area.

Bob
 
So, you make the seventh out of eight - 88%. Starting to look like an epidemic… Let’s see in which camp others fall.
 
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