left magneto timing tips, tools, or tricks?

[DavidC]

I am new to my 336 and my IA also has very limited experience with the io-360. Working on first annual - Today we were checking and setting mag timing and quickly discovered that the outer clamp on the left mag is very inaccessible. We couldn't get any wrenches or combination of wrenches in our tool boxes to fit in there. Thinking now about grinding and bending wrenches to try to make this work.

Does anyone have a good suggestion for a tool or combination of tools to get at this nut? Thank you.

David C

[wslade2]

Front or rear? Rear magnitude of order harder. “Stubbies” and “crows feet “ with extensions helpful. If something in the way, try to get it out including starters, lines, etc. Expect it to take time.

[mshac]

Right after I bought my Skymaster, I had to R&R the rear alternator. There's one nut that is almost impossible to reach in order to remove it. Took several hours but got it done, then the replacement alternator was bad, so we got to do it all again...

I took a bunch of pictures and posted them here. Do the same with your mag, and other owners will benefit from your experience.

[JAG]

David,

bending and grinding is usually the answer - as well as multiple different wrenches; stubbies, offset, etc.

I also have this half moon wrench in my tool box; have used it for most of my tough to reach areas. No doubt, patience and very small turns of the nuts is the main theme of these hard to reach areas

https://shop.snapon.com/product/Half...-Wrench/CX1820

Have fun! Jeff

[mshac]

Originally Posted by JAG

patience and very small turns of the nuts is the main theme of these hard to reach areas

Amen! And to this I may add: Small hands and a good back! Of which I have only one, but I still managed to get-r-done.

[DavidC]

Thank you for replies. This was on the RE. Turned out to be more going on than just restricted access to the magneto nut. Both RE mags were timed to 10 degrees advance - no idea why.

Because the outboard left mag nut was inaccessible it was never torqued correctly. We were able to rotate the mag by loosening the inboard clamp nut. When the mag was rotated the nut became accessible.

When timed at the correct 20 degrees, access to the nut was much better.

Thank you!

[bking]

Has anyone ever removed the door as shown on figure number 134, index number 16, located in the rear firewall to gain access to the rear alternator and magnetos?

[mshac]

You mean this one?

http://www.337skymaster.com/messages...2&d=1597183855

[bking]

Yes. On the last annual, my A&P removed and reinstalled both rear mags without utilizing the door. After I removed the rear engine baffling located over the mags, we had them out and back in and timed in about 3 to 4 hours.

[mshac]

Originally Posted by bking

Yes. On the last annual, my A&P removed and reinstalled both rear mags without utilizing the door. After I removed the rear engine baffling located over the mags, we had them out and back in and timed in about 3 to 4 hours.

I can't imagine doing the alternator without that access hatch. The early Skymasters didn't have it!!!

[wslade2]

Yes, I have no door and did both rear mags and alternator. Was difficult. There is an STC to add the door but it’s steep. I called about it after my travails.

[cessnadriver]

TO DavidC
Hello, welcome to the Skymaster world!
To review, the left mag as looking from the accessory side (rear of the engine).?
IF the 336 is laid out like the 337, I found that a 1/2" racketing box end will JUST fit. To start the nut, if removed, I found a 1/4" flex drive bend 90 degrees with a 12" 1/4" solid extension works best! Also I tape the nut in the socket so it doesn't fallout. On the right mag I found that a 1/2" box end wrench that I heated and bend into a crescent shape works well. FYI you'll only turn the nut about 1/6th at a time. Hope this helps!
Regards, BILLS