| Continuing with the fallout from the ISKRA starter. I replaced the failed ISKRA with a rebuilt TCM straight drive starter on my Legacy based on the recommendation from Niagara, vendor of the rebuilt starter adapters. My original starter adapter began slipping immediately using the new TCM starter and within seconds the starter was spinning and the engine was not. I then called Niagara for a replacement adapter which arrived next day as advertised. I discussed at length with Niagara's Ron Newburg on the replacement and the issues with the ISKRA that causes these problems. He was most helpful and provided lots of details and background on why this was occurring.
Last weekend the Niagara replacement starter adapter was installed along with the TCM starter. I needed to hoist the engine a few inches to remove the adapter which was actually quite easy once I got the hoist. We checked the starter adapter was engaging and releasing manually with a screwdriver per Niagara's instructions. The engine was at Mixture cutoff, no throttle and in the hangar when we went to do a dry start test with the new setup. The batteries were fully charged. Two of us watched as the starter was engaged. The prop quickly moved and started to slow down and after three blades I released the key thinking the batteries were dead. But, the prop was fully locked and would not move. The starter was removed and found to be ok. The engine was hoisted to remove the Niagara starter and the engine then became free again. The starter adapter was found to be seized and destroyed, pictures attached.
In discussions with Niagara, the potential source was indicated by Niagara to likely be faulty magnetos that somehow caused a kickback during the run that we visually missed or was so instantaneous that it overstressed the adapter. Accordingly, I removed the magnetos and sent them into a shop for inspection and repair as necessary and am awaiting a report. At this time, I have no usable Legacy and cannot reasonably attach another adapter without risking more damage so we're working with Niagara to figure out what is happening. At the moment, Niagara's position is that it has to be faulty mags because this happened on a Cirrus that was found to have a bad mag so that must be the problem. So, we're waiting for that magneto inspection report before trying to install another starter adapter.
So, the lesson here is that there is apparently a lot of risk in replacing a starter once the ISKRA has done its damage. One way to avoid the "its your magneto" problem would be to run the start process with the mags grounded or sparks disabled. At least that would remove that argument from the equation and it is a cheap and simple task provided the adapter doesn't get trashed. Is this failure from my engine, magnetos, Niagara's adapter? Hopefully, we can find out what happened.
Paul M Spruce Creek Legacy N357V
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