I am using an ST3 on my TSIO-550.  I considered the ST5, but, after talking with the folks at Skytek, chose the ST3.  The ST3 is lighter and smaller, and, even though it sounds like ball bearings in a coffee grinder due to its dry gear design, has worked perfectly now for 360 hours with not a drop of oil and no slippage.  It has plenty of power.

Note that you can’t just switch from an old Iskra starter to a skytek.  The Iskra has likely worn the starter adapter to a point that the Skytek will start slipping either immediately or within a few hundred hours.  This is not the fault of the Skytek.  You should install a rebuilt adapter when switching to the Skytek.  Not sure if this has anything to do with the oil leak, but it might be related.

Dear subscribers,

When my starter died last month away from home the local aircraft mechanic convinced me to put a sky-tec starter C24ST5 in my 4P. His arguments were availability reduced weight and state of the art design.

It had an external solenoid on it which interfered initially with my AC-compressor. But it has flange that can be rotated and I was able to fit it in (but it required a longer power cable from my solenoid plate).

When I put it on the first time the locating diameter fit felt kind of sloppy to me and the sealing O-ring looked very tiny. After I was home I noticed an oil leak (no drops on the ground but I can see that the engine looked wet on the rear side).

I pulled this starter twice now (a lot of fun!) and the last time I even put very thin film of gasket maker on the sealing diameter and on the flange ( I really made sure that all surfaces are clean and without damage). I still have an oil leak!!!

Question: is anybody using this sky-tec-starter? What experience do you have with it?

It seems to me that the locating diameter is a too sloppy fit and this o-ring on the locating diameter looks really tiny. Since the flange can be rotated on the starter the flange cannot be used as a sealing surface anymore. Once the oil passes the o-ring there is nothing that stops it.

I am thinking about buying the original starter again.

Thanks for your input

Ralf