Thanks for post feature available again: viewtopic.php?f=7&t=17581

Morris Magneto Half Tooth Out?

All Panhead related topics
Post Reply
fredotwowheels
Posts: 12
Joined: Mon Sep 23, 2013 6:02 am
Bikes: 1949 FL
Has thanked: 1 time

Morris Magneto Half Tooth Out?

#1

Post by fredotwowheels » Wed Mar 21, 2018 5:44 am

I'm having trouble with my MM74E. It seems like the base is either too retarded or too advanced, as if it is half a tooth off. I have the cover off the magneto for fitting, and it feels like I cannot get the lobe in the proper, just about to break position while the magneto is pushed in toward the cylinder where it should be while running. I have had it on the bike running before, but I'm just curious if anyone has had and issue with the magneto timing gear being slightly off?



RUBONE
Moderator
Posts: 4998
Joined: Sat Nov 15, 2008 4:09 am
Bikes: Multiple H-D, Ducati, BMW, Triumph, BSA,...
Has thanked: 11 times
Been thanked: 476 times

Re: Morris Magneto Half Tooth Out?

#2

Post by RUBONE » Wed Mar 21, 2018 2:20 pm

Did you have the top off the base? If so it could be rotated one flat of the hex drive off of where it was before. There are various positions it can go on and it will affect the position of the head relative to the gear allowing it to have more clearance to cases, cylinders, etc.

fredotwowheels
Posts: 12
Joined: Mon Sep 23, 2013 6:02 am
Bikes: 1949 FL
Has thanked: 1 time

Re: Morris Magneto Half Tooth Out?

#3

Post by fredotwowheels » Thu Jun 14, 2018 9:14 pm

To return to this, just before work today I took a quick look at my mag timing.

I noticed that the back corner lid screw, the one closest to the cylinder, would lightly spark every once in a while! I had this bike running before, and it pulled really hard, but since having the heads off I couldn't get the power out of it I used to. Once I saw the sparking, I remembered that I did not have that screw in when it was last together, because I when I was timing, I wanted to see the magneto cam lobe and the timing mark at the same time. I would place the lid on the magneto after it was already locked down and could never get the last screw in, the one closest to the cylinder. Anyway, I haven't ridden it yet, but it is idling better!

I have done a lot of research, but this has never come up, so I figured I would at least mention it for someone to check going over the same things I am.

I am not worried about the lid, I live in SoCal and we don't see much rain, but perhaps you could locate a nylon bolt for that back corner if it worries you only running three. I will give an update if this helps with the ride.

EDIT: BTW, I spoke with Morris Magneto and they told me between the adjustable baseplate, and turning the flats, there should be overlap of degrees of rotation, so it is not possible to be unable to have this magneto sit at perfect timing.

melchorz
Site sponsor
Site sponsor
Posts: 46
Joined: Sun Feb 09, 2014 12:04 pm
Bikes: 1963 Harley FLH; 1974 BMW R90S
Location: Pennsylvania

Re: Morris Magneto Half Tooth Out?

#4

Post by melchorz » Sat Jun 16, 2018 8:42 pm

I'm not sure why you're getting a ground-to-ground spark.
Make sure the unit is super clean including the screw threads that hold the coil in place.
Make sure the kill switch terminal is isolated from the case.
Make sure internal wires are routed without shorts.
Do you have a clear lid? It helps to spot if the narrow lobe moves before the head rests home on the base. Also the Morris magneto tester works great (you can find the same thing cheaper online on a aircraft supply site...they use magnetos, too).
You can use an Allen head screw and a cut-down hex-key to get to the back lid screw.
Be patient, took me all night to finally get mine in the position I wanted. I also referred to the video several times.
So the trick I use to move to the next timing position is to mark the position of a point with a sharpie on the base. Then carefully lift the base without turning the base until the gear disengages and the hex stops turning. Then turn the hex to the next flat (plus a little) and lower the base back down. You can check the mark to see if the position changed from a point to a flat. Keep trying. Keep moving to the next timing position (flat or point) until it drops in where you want it.
One problem I had was the old point set leaf spring did not have enough tension to hold the narrow lobe to just before that point break position. If you observe a new set of points, the spring is straight. So you may need to re-shape your spring.

Post Reply

Return to “Panhead”