Motorcycle Repair: I recently bought a 1983 V45..., 30 amp fuse, regulator rectifier

Question
I recently bought a 1983 V45 Magna, I've put about 1500 miles on, and it has about 13800 on right now. I'm experience a problem with loss of power and at the same time the tach will go wild – just bouncing all over the rpm range, then it will settle down but the power loss is still there and I have to stay on the throttle so the bike won't cut out. I'm going through each electrical system and hopefully I will come across the problem. I've run the electrical tests as specified in the shop manual for the regulator/rectifier; pulse generator; ignition wires and coils. I've replaced spark plugs with new ones, ignition and coil wires with ones I got at a salvage yard also tried regulator/rectifier from the salvage yard, all these tests/changes where done separately so not to confuse or create new problems. I also disconnected the fuel pump and ran the bike off an aux tank.  A couple of other things I replaced as I was checking the wiring – the fuse link for the main 30 amp fuse broke and the three prong wiring harness that went from the alternator to the regulator/rectifier was fried so I replaced those three connectors. All the other fuses look and seem to work fine. Maybe there is a sensor gone bad? Any help would be much appreciated.  

Answer
Tony, this is an odd one, for sure. The fried stator connector is not uncommon on the older bikes and can often take out the reg/rectifier and or the stator itself. Check the www.electrexusa.com site for more assistance on the charging system.
You didn't mention the charging output values, so I don't know if this is the primary cause or not. If your bike has a fully charged battery and the charge rate is to specs, then the misfire could be from somewhere else. The tachometer issue coinciding with the misfire seems to indicate a relationship there. I don't have any wiring diagrams for these bikes, so don't recall where the source of the tach signal is and how it could be related to the misfire.
I wouldn't be surprised if the diaphragms for the petcock and or the air cut valves on the carbs would be faulty, causing a misfire, but that should not be related to the tachometer signal problem. Try disconnecting the tachometer signal wires from the meter, so you can isolate the problem further. The tach signal can come from either the stator or the ignition system, depending on how they chose to measure the signal.
Check all the ground paths and wires for good clean connections. Check the stator for suspect shorting, perhaps when hot and for matching output on all leads of the stator windings.

Bill Silver