Indian 249 Scout Mag Problem

[Skirted]

Original Edison magneto on this 249 Scout. When I bench test the mag by clamping and spinning it by hand I get nice bright blue spark from plugs connected to both ports. When I bolt it on the bike I get no spark. Everything is same, just bolted on bike instead of clamped in vice. Is there something obvious I’m missing here? I had it off 3 times just to make sure it wasn’t some freak thing.

[tfburke3]

Are you connecting the ignition wire after installation,if so check that the wire has no continuity to ground in the run/on position ,or just try it with the wire off.
Tom

[Rubone]

When bolted on is it insulated in some way, gasket, paint, etc?

[Skirted]

Are you connecting the ignition wire after installation,if so check that the wire has no continuity to ground in the run/on position ,or just try it with the wire off.
Tom

Did not connect ignition wire Tom

When bolted on is it insulated in some way, gasket, paint, etc?

I thought about that. Not gasket and Verified with ohmeter so no problem there.

[tfburke3]

Maybe you are spinning it faster in the vise than with the kicker.
Mags can be a pain,but are good if you dont have electric on the farm to charge a battery.
Tom

[pisten-bully]

Is there something obvious I’m missing here?

Jason (well you asked for it!).....is the plug grounding properly when it's on on the bike? :-)

[Skirted]

Maybe you are spinning it faster in the vise than with the kicker.
Mags can be a pain,but are good if you dont have electric on the farm to charge a battery.
Tom

crossed my mind but I was amazed how little speed this one took to create spark. Also with no plugs in engine I’m kicking it over pretty fast and figure it’s spinning much faster but I kicked slow and fast just to see if any difference.

Jason (well you asked for it!).....is the plug grounding properly when it's on on the bike? :-)

yes Harry definitely made double sure it’s grounded and even grounded to mag case just for sheetz and giggles.
This is my second Vertical and thought I got pretty well schooled on mags from the first one. Got this bike last fall on pick. Only sheet metal on it was gas tank but we found nearly everything for it scattered about in the basement. Had a big knobby tire on back. Had it running last fall after cleaning seeds out that were stuck under valves holding them open. Ran good but then sputtered home and it died pushing it the last bit. My wife named it Otis. I got it all back together over winter so it looks presentable and figured the ignition problem would be simple and we’d be riding it by now. These have a battery and gen for lights and I even disconnected both just in case there was some weird short reacting with magnetic field. That’s reaching I know but this too strange. Sometimes when something seems complicated something simple is overlooked but the simple list is dwindling.

[Rubone]

Same plug wires as the bench test? Not resistor are they?

[Skirted]

Same plug wires as the bench test? Not resistor are they?

Yes same wires. They are copper. I did the R&R test the 3rd time with a different set of wires I had and result was same. OK on bench, no spark on bike. I have to pull the cap to install the mag, but leave the wires attached to cap so there is no disconnect and reconnect. The cap seats perfectly and is in good shape. Other than the gear being meshed and in contact with its driver gear and the housing being bolted up I can't see any other difference.
If I get desperate I'll pull the mag from the other bike and try it but hate to disturb things when working. Thanks

[tfburke3]

Any chance there is some end to end or side play in the shaft that is not having an effect when spinning by hand but some binding or side load installed causing the problem?
If you mounted with cam cover off and spun it by hand,without the idler or cam(no to familiar with cam chest on 249)what would be closest to the in the vise test.
Tom

[exeric]

For what it's worth, Jason; I had a Bosch ZEV magneto that worked great when grounded out on my drill press, and turned with a drill motor. Installed on the bike, it was too weak to reliably keep the motor running. I sent it to a magneto rebuilder in Minnesota and he found micro cracks in the commutator (I think that's what he said). Regardless, he said it was arcing internally, and not delivering a full jolt to the spark plugs. I gathered that isn't uncommon in magnetos that used Bakelite components.

[Skirted]

Any chance there is some end to end or side play in the shaft that is not having an effect when spinning by hand but some binding or side load installed causing the problem?
If you mounted with cam cover off and spun it by hand,without the idler or cam(no to familiar with cam chest on 249)what would be closest to the in the vise test.
Tom

Don't recall any side to side play specifically but did not check end to end so I will do that. Agree it might be time to pull the cam cover. I may try swapping the mag from the other bike first. Having the two on bench side by side will also allow a close comparison.

For what it's worth, Jason; I had a Bosch ZEV magneto that worked great when grounded out on my drill press, and turned with a drill motor. Installed on the bike, it was too weak to reliably keep the motor running. I sent it to a magneto rebuilder in Minnesota and he found micro cracks in the commutator (I think that's what he said). Regardless, he said it was arcing internally, and not delivering a full jolt to the spark plugs. I gathered that isn't uncommon in magnetos that used Bakelite components.

Thanks Eric - every comment helps! I was thinking possibly a weak magnet or other generating deficiency but the bench test spark is so bright with just a quick flip I should get at least something once in awhile on the bike. I went as far as turning lights out in garage to see if there was even a minimal spark that couldn't be seen with ambient light.

[exeric]

As I have said before; the magneto is one of Satan's favorite creations I hope you find the problem, Jason. When you do, I think everyone would like to know what it was.

[Skirted]

Update: Otis Lives! I hadn't tried spinning the mag with a drill so did that just to see how it reacted and the spark looked great. After exhausting all the ideas I started thinking the mag itself was at fault despite no smoking gun so I pulled the one from the other bike and installed. Works fine. I did try the hand test with the replacement just for comparison and it appeared about the same, but thought if anything I detected it did spark a wee bit easier. So at this point I'm thinking the quick flip of the wrist doing the hand test allowed it to spark but the action of the kicker and slower start rotation speed apparently wasn't quite enough for it to spark which Tom had mentioned as a possible cause. Odd circumstance because I was kicking it pretty fast...or so I thought.

The coil ohms out exactly same as the good one so would that mean the magnet has lost some of its strength?

Before and after pics of Otis

[pisten-bully]

Before and after pics of Otis

Nice! I can't help but think what would have happened if Indian had had their sheet together and got those bikes to sell in larger numbers, they're kind of neat looking in a British sort of way, nice job on that one Jason!