As I mentioned in my last blog post the bike wouldn't start, so finally i decided to troubleshoot the starter. The ignition was missing so when I ordered the ignition I also ordered the shop manual.
I had this as a reference
Here was the problem - when I pressed the starter the "armature shaft" should engage (i.e. move forward) but would not spin. i must admit at this point that I have a fairly sordid history with Guzzi starters. And by that I mean they usually stump me and piss me off. I also feel like its ALWAYS the same damn problem! I pulled the starter and attached solenoid off the bike to see what was going on.
I will link the bench test instructions shortly but by pulling it off the bike I could test it. I clipped the positive cable to the small tab on the solenoid and when I grounded the large nut, the shaft would engage. When I had positive to the large nut and ground the starter nothing happened and at that point it should have spun. I went ahead ahead and took the cover off the starter. Under the cover are four lead brushes (they are blocks that are clipped in and easily removed). I started by removing two of the brushes and lightly sanding them to ensure they had good contact. I reassembled it and bench test again. It spun! I thought at that point it was fixed and I'll admit I fairly proud of myself. I bolted it back on and the same thing.
I pulled it back off and held it against the frame so I could watch and sure enough it simply engaged and didn't spin. What the hell? We had another starter in stock and I hooked that one up and it also only engaged and didn't spin. Back to the the bench...
I again tested it and it spun and engaged but not together! The instructions showed a way to use a wire and clip the two points together and you should see it engage and spin but i couldn't get that to work. I also couldn't get the shaft to engage by just being grounded to the starter which the instruction alluded to.
Getting frustrated I thought it was the T clip in the solenoid not transferring power to the second large nut. So I decided to disassemble the solenoid and clean it. DO NOT DO THAT. Thankfully i couldn't use a soldering iron to get into it. Although I tried my best! Finally I said "Eff it" and headed home a broken man.
The next day I came in and wasn't going to touch it until after lunch. With a clear head I decided to take it from the top before sending the starter off for a rebuild. Within 5 minutes I had the problem solved. I grabbed the shop manual to review the wiring thinking something there might be wrong. Simply this was the problem. The starter has to wires going to One essentially go from a small clip to the starter button. The other is from the large nut (not connecting the solenoid) to the POSITIVE side of the battery. The only ground is the starter being bolted to the frame. I had that nut connected to the negative side of the battery thinking it needed that ground.
With Bradley checking spark and myself filling the tank and checking carb leaks we had the bike running in 30 minutes!
I'll post video shortly... it sounds radical.