re-installing magneto

[rigidpanman]

i sent my mag to joe hunt to have it checked out,come to find out i needed a new magnet.now that i have it back i want to make sure i installed it correctly,so here is what i did.i took the cover off the front intake pushrod tube and rotated the engine with the kicker until the pushrod started going down,while continuing to bump the engine i stuck a flathead screwdriver in the timing hole so i could catch the slot in the flywheel,once i did that i put the slot in the center of the hole and installed the mag with the small lobe just about to break the points open with the mag at full retard.my thinking on this is so i could rotate the mag forward to get the correct amount of advance out of it when i got the engine running,however,im thinking that might not be the right way to go.any comments or suggestions?thanks

[StueyC]

Early (Mounting) Model Harley 74 Magneto Instructions

1. To Install the magneto remove the spark plug from the forward cylinder. Next remove the distributor cover on the stock ignition still in the bike. Crank the engine until #1 piston is coming up on compression and the points begin to open. (This can be accomplished with a feeler gauge, timing buzzer or ohmmeter.) This should put you very close to 32 to 35 degrees advance. Take the bike out of gear now and leave it that way until you have the magneto in stalled and are ready to start it. Some stock ignitions have built-in advance mechanisms and after you have installed the magneto, you will have to alter the timing to compensate for this extra advance.

2. Remove the four Allen socket head screws, holding post hole adapter to magneto head and remove post hole adapter from head.

3. Insert post hole adapter into engine making sure that it bottoms and is perfectly flat on machined surface on engine.

4. Make absolutely sure that nothing hits the adapter or obstructs it from bottoming on the machined surface on the case. If it does not bottom correctly, relieve adapter or cases so that it does. If you have to relieve the adapter, make sure to relieve it enough to have sufficient clearance to advance or retard for timing purposes.

5. Remove the clockwise cap on the magneto head and turn the breaker cam so that the small lobe is about to engage the rubbing block on the points in the direction of rotation. While maintaining this cam position on the magneto head set the head on top of the adapter. (Most panhead models will have to be mounted with the coil hold down screws on the magneto facing toward the front of the bike and parallel approximately with the barrels.) Most other models will mount with the coil hold down screws facing straight out the side. Once again make sure that the unit clears.

6. If you have sufficient clearance and the mag does not hit anywhere, apply Loctite to the four Allen socket head screws and install them tightly, affixing the adapter to the magneto head permanently

7. Install your hold down clamp but leave it loose enough to still turn the magneto with hand pressure.

8. Using a clean feeler gauge, .0015, or a timing buzzer, rotate the magneto counter-clockwise until the points open, and lock it down.

TROUBLE SHOOTING


Hard Starting:
(A) spark plugs gapped too wide. Should be .018.


(B) carburetor float level too high or carburetor running over and fuel fouling plugs.

(C) plug wires faulty. Note: both plug wires must be hooked up for magneto to fire because of double-ended dual secondary-wound coil. This is normal and is basically the way the coil was designed.

(D) magnet discharged. Generally will occur only when battery current is hooked up to ground post. Return to Joe Hunt.

(E) points dirty. Use carbon tet and point stone to clean gap .012 to .015.

(F) cap cracked or carbon tracked. Note. Good magneto operation requires absolute internal cleanliness. Gasoline, dirt or metal contamination will seriously damage magneto. Keep It clean!

Make sure that you do not hook up anything with the exception of your kill wire to the primary post coming out of the side of your unit. Do not hook any live voltage except for a timing buzzer up to this post. Failure to comply will seriously damage your unit and we wilt not be responsible. Gap plugs at .018 and start bike.

On Panhead Models:
To mount your Joe Hunt magneto, it will be necessary to remove and. relocate your relay if it is mounted on the boss that is cast into the cases and located on the front of the engine above the generator section. It will also be necessary to remove partially or totally the boss that the relay sits on. This can be accomplished with a hacksaw with the blade turned sideways. Cleanup can be done with a file, disc sander, hand grinder, emery paper, etc. The casting should be thick enough in this area, so make sufficient clearance for the mag. If necessary, a small amount can be relieved on the bottom of the magneto. Some fins may also have to be relieved slightly for clearance. This can be done with a hand grinder, cape chisel, etc.

On other models:
Fins will need to be relieved slightly in the area directly behind the magneto. This Is to get clearance to advance and retard. For pushrod housing clearance you may have to dimple your pushrod housing or slightly relieve the side of the magneto and cap in the area that contacts with the pushrod cover.

[rigidpanman]

thanks for the reply,ive read that but since i dont have a distributor already in the motor,i have no way to relate to those instructions.

[Panacea]

Just do as you would to time the motor, front cyl. on compression stroke, timing mark in the timing hole. With the cam lobe in position to start opening points, insert timer so the head will be in the middle of it's adjustment range. Keep in mind it will rotate clockwise about 20 deg. when it engages the helical circuit breaker drive gear. Once inserted, check and adjust timing. If you don't like where the head winds up sitting, pull it out and adjust accordingly. ( I hope yer not grinding off your relay boss), somebody did that to mine...Mike

[rigidpanman]

thanks mike,ill take a look at that,i ground off the relay boss about 23 years ago when i first installed this thing.back then nobody cared.

[kitabel]

20° is about the rotation caused by the gears meshing as the mag gear goes down (the ignition gear in the case and mag head do not move). If it doesn't "catch" a tooth, you have to twist the mag head CW or CCW until it does, which is another distance. The span between 2 teeth is 36°, so mid-way is about 18° etc.
Sometimes (especially in a rebuild or new installation) the mag won't advance enough (strikes the head/tube too soon when rotated), and if advanced 1 tooth it's too much.
In addition to the 1 tooth 36° span, there's another adjustment: the position of the hex key that drives the mag from the shaft. Each hex flat is 60°.
But how does that help? Use the difference:
Moving 1 hex flat forward, then 1 shaft tooth back gives +24°.
Moving 1 hex flat forward, then 2 shaft teeth back gives -12°.

[rigidpanman]

kit,i had the idea while i was at work today that i may be one tooth retarded,which i agree is 36 degrees,however i didnt take into account the hex drive,i do think it may be retarded too far,i pushed the mag all the way advanced a little while ago and still didnt get a hit,i think im going to advance it one tooth tomorrow.

[rigidpanman]

kit,also im going to assume you mean advanced when you say forward and retarded when you say back.

[kitabel]

Yup - always worth a try, let us know if it works.

[rigidpanman]

yea,ill keep ya`ll posted for sure

[rigidpanman]

ok guys,got it running,it appears i had the cam lobe 180 out,only issue i have now is after letting it run for a couple of minutes i cut it off and couldnt restart it,i know its just a matter of getting the kick starting method down.one more question,when i time it with a light should it be idling or at a higher rev?thanks for all of your replies and help

[Panacea]

Set at full advance..Mike

[RUBONE]

one more question,when i time it with a light should it be idling or at a higher rev?

With a fixed advance magneto the timing is set at full advance (points just breaking when timing mark in hole) so rpm does not affect it in any way. It is full advance at idle or at 5000RPM!
Robbie

[rigidpanman]

groovy,i just set it with the line in the hole and im good to go.thanks

[rigidpanman]

ok,new issue.since getting it started on monday i have not been able to get it to start again.i want to hook up my ohmeter which has a buzz feature to get tdc dead nuts on.question is where should i connect the leads off my meter to the mag?thanks again