Originally Posted by rmd
For what it is worth...there is at least one case of the internal timing being off.
My ignition timing display indicated that the Plasma II+ went to 45 or 46° of advance, but the engine sounded and felt fine. Increased CHT seemed to confirm that the timing was too far advanced, but I did check timing with a timing light and followed all of the other trouble-shooting steps Klaus put in his manual.
After performing all of those steps, I gave Lightspeed a call and they told me to send it in for repair. They replaced a capacitor to fix this problem and upgraded some other minor, unspecified components and had it back in the mail the day after they received it. I don't recall the cost, but didn't find it to be unreasonable.
Interestingly, a couple of A&Ps walking by as I tested the timing commented that they thought the engine would really sound and act horribly if the timing was advanced that far. I wasn't smart enough to know one way or the other, but thought I'd pass along the information.
Yup, its happened to me too. I discovered my timing on the LS to be stuck at 43 deg BTDC.
It was bit insidious in my case. I received my newly repaired engine with new cylinders in the spring some years back. I watched the temps come down during break-in. Just when I thought the break-in was complete, I began seeing the temps go back up. This was coinciding with warming summertime temps. Once I had trouble maintaining CHT's below 380, I knew something was amiss.
I bore-scoped, checked baffling, checked the Vernatherm, etc. Finally something on this site tipped me off to check the timing. The magneto on the right was right at 20 deg BTC, perfect for the angle valve. The LED on the LS also indicated perfect timing. Shot it with the strobe light and voilą, 43 deg BTDC. Not sure if it was in the MAP circuit or not, but there was a capacitor blown in the box. Klaus repaired it for a reasonable price.
That was my 3rd failure with my LS. I've had two of the Hall Effect sensors that go in the magneto hole go bad and the aforementioned capacitor. So I'm not exactly thrilled with it, but I do have 1800 hours on the system. When it works, it works exceedingly well. But when it doesn't, it's game over.