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-   -   Left slick mag with impulse coupling timing (https://vansairforce.net/community/showthread.php?t=135224)

Ron Springer 08-31-2018 02:33 PM

Quote:

Originally Posted by krw5927 (Post 1284952)
Are you certain the magneto is timed to 28 degrees BTDC? This is 3 degrees advanced timing, and from the forums over the years, doesn't seem to be a very common practice.

Well, I didn't say what engine I was talking about. This is for a Continental O-200 and the data plate is stamped for 28 deg BTDC. And the magneto is a Slick 4300 series.

jrs14855 08-31-2018 02:59 PM

Mags
 
The 0 200 is a relatively low compression engine and will tolerate far more timing advance than the high compression Lycomings. The 0 200 in the F1 Racers commonly run VERY high advance settings. However almost all of these aircraft are trailered and most only fly an hour or two a year.
I have no recent experience with the Slick mags but the 500 hour overhaul definitely applies. You need to check with a specialty shop about the impulse.

deek 08-31-2018 03:38 PM

Quote:

Originally Posted by jrs14855 (Post 1058928)
.
Aircraft Magneto in Helena MT is a highly regarded shop. Just ask for a check of impulse and internal timing. $200 plus/minus against the cost of a new engine if the impulse comes apart.

They're in Missoula, not Helena:)

Ron Springer 09-01-2018 10:28 AM

Follow Up
 
Follow up ....

I repeated the same test of where the mag snaps on a different plane with a similar new, rebuilt Slick mag and it snapped very close to TDC where I expected. So, I don't think that there is anything normal about my result where it snapped well after TDC on my plane.

I also talked to the builder of the plane and was able to piece togther the history of the magneto. It was installed new on June 23, 1995 and that was 1091 hours ago. It has never been opened and serviced to his knowledge in all that time (no internal timing adjustment, no 500 hour inspection, etc). I think we got our money's worth out of this mag, so a new one is being ordered.


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