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SA 200 magneto rebuild

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3K views 19 replies 6 participants last post by  smithdoor  
#1 ·
How difficult is the Fairbanks magneto to rebuild? I’ve rebuilt carburetors and automatic transmissions but I’ve never been into a magneto. Is there info out there on how to do it properly or is it better to send to a rebuilder and if so, who would that be?
 
#2 ·
Been looking around at rebuilt mags and from what I've found, the cost seems to be ~$300 + shipping and my core. This welder will be for occasional use, I'm not a welder by trade and will not use it every day. With that said, is a magneto or electronic distributor more reliable in that situation? I realize one of the pros of a magneto is that the machine can be hand cranked in a dead battery situation which is appealing to me. Cost wise, by the time I add plug wires and new plugs to the cost of rebuilt magneto, I'll be near the cost of the distributor kit cost so cost between the two is pretty much a wash. So, in my occasional use situation, what would the preferred ignition system be?
 
#3 · (Edited)
I don't believe they are anymore difficult than a carb but mag parts prices and availability may differ.

The mag principle is simple but seems like black magic.

One word of caution: be careful especially when rotating that little sprung sprocket.

Mags are reliable and I believe they don't miss at hi revs compared to distributors but I could be wrong. I had an Olds with dual points for running near redline
 
#5 ·
And aircraft use redundant magnetos for backup. And for some reason , I think magnetos don't miss at hi rpm's. No?
 
#7 ·
My magneto is good but I looked into parts just to understand what it would require if it failed. IIRC, unless you are rebuilding the entire unit, cost to re-point it etc was not so bad. Are you sure yours is in need of Everything?
 
#9 ·
If your mag is good put a new cap on it and wires and forget about it if it is bad I take mine to local mag shop they tune it up magnetize the magnet about 1/3 to 1/2 the cost of a rebuilt . I am betting there is a local shop somewhere close I have had machines with a mag never ever had the mag off biggest thing with a mag is to use wire wires !
 
#11 ·
Unfortunately, there's no local mag shop. I do have a contact at a starter/alternator rebuild shop about a couple hours away. I'll reach out and see if he rebuilds mags. Living in a rural area has its advantages, but multiple options for service work isn't one of them.
 
#12 · (Edited)
Here's some cool old airplane magneto stuf . One pic shows 3 magnetos. I knew aircraft used redundant or two mags
The third is a booster mag for starting old time aircraft I guess. I can only load 5 pics per post so the ten pics will be in two posts.


Edit. Pics

Pics are reverse order.
 

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