Last weekend I took Ilsa for a bit of quality time doing a 4 day blitz around Lakes Huron and Superior. Trip went well until the second night when the engine momentarily shut down as I was pulling into a gas station in Grand Portage, MN. Nothing serious, it just stopped running, and restarted immediately with the starter.
The next day it quit again, twice, at 75+mph. Both times it started immediately after turning the ignition switch off and back on again. Now she had my attention. I had seen the same thing almost three years ago. The ignition switch was acting up again. Great! In the middle of the very rural west end of Lake Superior at least 1200 miles from home.
Symptoms were a very momentary loss of electrical power killing the engine, which as the trip went on for the next two days progressed to requiring the ignition switch to be cycled several times to get the idiot lights to come on and the starter to respond to the pushbutton. Nonetheless, she did get me home.
Bike sat all week and Saturday I tried to start it, but it took about 10 minutes to get it to fire, and applying either of the brakes immediately killed the engine and the idiot lights which barely lit up when the engine quit. Then the starter refused to turn even when the idiot lights were at full brilliance when the key was turned on. Strangely, the headlight worked even when nothing else did.
Sunday morning I decided to take care of the problem. I had left the battery on the charger overnight so I knew I had a full charge. Tried to start, nothing. Connected my jump box, still nothing. Well it's not for lack of a good battery.
Next was the grounds. Checked them and they all were good and clean. No corrosion or dirt anywhere, so that wasn't the problem. I now knew it was the ignition switch, the same one that gave me trouble 3 years and about 25,000 miles ago.
It's a pain in the ass to get it out, so I figured that since I had never serviced the starter on this bike and it is easier to get at it than the ignition switch I would pull it and see what the brushes and the commutator looked like. Even though I knew better, I was hoping that there was a bad ground through the starter causing my whack.
Pulled the starter, brushes were nearly 11mm long, virtually new. Cleaned the commutator with electrical cleaner and a brown Scothbrite pad, greased the bearing, reassembled and installed. Just as I expected, no joy. Up to this point I had 1 1/2 hours invested. Now the fun part, the ignition switch.
Pulled the tank back, disconnected the RT dash pad, found and disconnected the connector for the switch. removed the switch from the pad, and followed the disassembly instructions here:
http://www.eilenberger.net/K75S/IgnitionSwitch/Sure enough, there was a big glob of black chit on the center contacts which I polished off with a bit of 1200 grit paper and DeOxit. After cleaning the rest of the contact points in the switch I reassembled it and put it back in the dash pad. A quick test and the engine started in less than one revolution and settled into a smooth idle. Applying the brakes did not kill the engine and all electrical equipment worked properly(turn signals, headlights, grip heaters, etc.). :clap:
I recall using a tiny bit of silicone grease on the contacts the last time I was in there and suspect that the high current the switch main contacts carries burned the grease causing high resistance. This time I opted to not apply anything to the contacts as there was no evidence of any water or corrosion anywhere in the switch.
If you have a high mileage Motobrick and have never been in there, I would suggest that servicing that damn switch is an excellent winter preventive maintenance project. Start to finish on my RT it only takes about 2 hours or less and will give much peace of mind.
