The “UV” light bulb I ordered arrived on Thursday. i took a day off work on Friday to look for oil leaks. I was disappointed to see that while some things ahead of the firewall highlighted nicely under UV light, oil wasn’t one of those things. Oh well. I cleaned everything up as nicely as I could, then went flying.

After landing it was clear that there was no evidence of a large oil leak, but there was still some oil coming from something.

Saturday I took another look, and noted a drop of oil in a strange place, on the bottom of the Hall Effect Module for the Light Speed electronic ignition system. Everything below there had sign of oil, and everything above was dry. Hmm. I removed the cover on the back of that module, and found roughly one teaspoon of oil inside, where there isn’t supposed to be any oil at all. The circuit board attached to the cover was contaminated with oil. The oil seal around the input shaft had obviously failed, allowing oil to sneak in from the accessory case. Drat.

At first I hoped I could find an oil seal locally and change it myself, but online research suggested that it really should go back to Light Speed so they could do the job. This is apparently a fairly common issue with the Light Speed Hall Effect Modules. The good news is that the unit will tolerate a lot of oil inside, and I found no reports of any adverse effect on the operation of the ignition system. But, I’m not sure that the ignition would continue to operate correctly if enough oil got in there, so I need to get this sorted out ASAP.

I boxed it up and shipped it via UPS from Ogdensburg on Sunday afternoon. I’m hoping they can turn it around quickly and have it back to Ogdensburg by Friday afternoon, so I can reinstall it on Saturday. If I have a repeat failure I’ll either switch to the other option for crank position sensing - magnets on a plate attached to the crankshaft, with sensor bolted to the crank case, or ditch Light Speed ignition completely and install a second PMag.