M

markscogg

Well Known Member
I am trying to install a new slick 4371. My mechanic disassembled the old mag, and I am wondering if there is a part missing.
The gear is slightly loose when installed on the mag. Is there a special washer missing from these photos?
Gear will move a few thousands end to end and radially with the castle nut snug.

4371top.jpg


4371end.jpg


Thanks
 
Normal

Thanks Walt,
Quote from your link:
"On impulse coupling magnetos, there should be .010 to .020 inch end play on the gear. This is normal and not a reason for concern."
 
Magneto Gear

Yes, the gear is supposed to be a little loose. Nut torque is 120-300 inch pounds. Dont clamp the magneto or inpulse coupling during instalation. Hold/clamp the gear with somthing soft/non-marring, torque the nut to a mid-range value, tighten until the next hole lines up for the cotter pin, bend cotter pin to a "smile" shaped curve and install. Good luck, Russ
 
I know this thread is a couple of years old, but it seemed like a logical place to ask a similar question.

Our -7A needed a new Slick 4371 mag and I'm not sure how to determine the correct orientation for the drive gear. I know it'll only fit with the gear away from the mag and towards the engine, but it is not rotationally symmetric and can be installed rotated to approximately 3 O'clock or 9 O'clock in the photos from Mark's original post.

How do you determine which is correct or does it not matter and the correct meshing of gears happens when the mag is mated with the engine?

Also, how do you keep the impulse coupling spring from wrapping up when trying to torque the nut?

Nice tip, by the way, of bending the cotter pin into a smile to install it - that had me scratching my head too until I came across this post.

Thanks, Rob
 
correct way to attach gear

Rob, you will need to do a dry run as you won't be able to time the mag to the engine if it's on 180 out. So, install the gear, torque to spec but leave the cotter pin out. Internally time mag and install on engine. If the mag will time to the engine, the gear is on correctly. If the mag wont time to engine, remove mag and re-mount gear the other way. Re-install and again time mag to engine. If all is well pin it.

Allen
 
Allen - Thanks for the quick reply. Sounds like a straight-forward approach.

Bob - Thanks for the caution - no impact wrenches here. It would be kinda cool to see what would happen if I tried it on the one that's going back to Spruce for the core though :)

Regards,
Rob
 
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