What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Unison service Bulletins now Lycoming Mandatory Service Bulletins

RV6_flyer

RV6_flyer

Well Known Member
Benefactor
In May, Unison issued Service Bulletin SB2-08 for Slick 4300/6300 and LASAR 4700/6700 Mags. It affects Slick and LASAR mags with serial numbers 0610XXXX through 0804XXXX for the breaker point cam. Eleven days later, they came out with SB3-08 for the same mags with serial numbers 0409XXX and up with respect to the carbon brush.

June 3, 2008; Lycoming now has two Mandatory Service Bulletins for the above two Unison service bulletins. I cannot share my Unison subscription or my Lycoming subscription but Lycoming publishes some of Mandatory Service Bulletins on their web site so everyone can get the info for free.

http://www.lycoming.textron.com/support/publications/service-bulletins/pdfs/SB584.pdf

http://www.lycoming.textron.com/support/publications/service-bulletins/pdfs/SB583.pdf

The cam is made of plastic and retails for sixty cents. The carbon brush retails for just under $6.
 
Has anybody wondered why the SB number don't match up, but are concerning the same SB? One is a revision of the other, but the numbers don't match.
 
Geico266 said:
Has anybody wondered why the SB number don't match up, but are concerning the same SB?
Click to expand...
Nope. I've got duel P-mags. You would never catch me running those old mags, they could kill ya! :rolleyes:

Sorry, I just couldn't resist after all the grief I was given a year ago about the P-mags. (Now with 165 trouble free hours!)
 
not the same SB

One SB concerns premature wear of the breaker point cam. The other is about premature wear of the carbon brush.
A simple verification of your ignition timing takes care of the breaker cam SB. A change of more than 4 degrees from the original setting indicates cam wear and a need to replace it. Recheck periodically per the SB.
The other SB involves disassembly of the mag for visual inspection of the carbon brush, the contact arm, a buildup of carbon dust, and damage from arcing. Recheck periodically per the SB.
Notes: Your 1 year warranty may still be in effect. However, the replacement parts will be the same as the original items as new parts are still in development. One SB concerns mags built starting in 2004. The other goes back to 2006. Unison issued the SBs in May. Lycoming did a CYA by making them Mandatory SBs in June.

I have 50.8 on my -9A. My A&P said to:
1. verify mag timing. (done and no change from 25 deg BTDC)
2. keep flying.
3. order replacement parts anyway because they're cheap.
4. He and I will inspect and replace the suspect parts, if req'd, when they arrive.

Steve
 
Spoke with Bart Lalonde at Arlington yesterday re the SB.

Right now, if you replace the brush, you will have to reinspect according to the intervals in the bulletin. He's awaiting a "permanent" fix from Unison, so that you can eliminate the requirement for periodic inspection.

If you have an AeroSport engine, and need more info, call Bart.

Vern
 
yakdriver said:
Hey Verne, That was me sitting in the chair when you walked up and we were discussing mags. Don
Click to expand...

**thread hijack**
Hey Don, I swung by your camp as I was heading out Saturday. Seemed like a good fly-in, but reduced numbers Brian
**back to mag discussion**
 
You must log in or register to reply here.
Back
Top