Sudden bog while riding

I wasn't sure which forum to put this in because I'm unsure of the problem lol.

So I was riding to work on the freeway this morning, when suddenly my bike started bogging and was really low on power.

This happened while I was cruising at about 70. It was working fine, then as if someone flipped a switch, it just started bogging. Feels ignition related but I'm unsure

It seems to only do it past about 5 or 6k rpm. Also, once it starts bogging, my tach needle goes haywire. Maybe a faulty coil or faulty connection??

I checked the ignition advancer and it moves freely, all connections at the ignition coil look fine, the plugs aren't fouled, ignition wires are good, fuses are good, all grounds are good.

I'm at work so I haven't tested anything with a multi meter.

Any possible insight??

Test the voltage at the battery, ignition switch, kill switch, coils and on connectors plugs.
A weak battery, regulator/ rectifier can cause a voltage drop (my tach needle goes haywire).and a weak spark.

Scirocco wrote: Test the voltage at the battery, ignition switch, kill switch, coils and on connectors plugs.
A weak battery, regulator/ rectifier can cause a voltage drop (my tach needle goes haywire).and a weak spark.

Okay I will definitely check voltage at those locations once I get some time tonight. Do you think that a weak battery can cause a weak spark at specific rpm??

I would first suspect a faulty ignition or kill switch contact. One test you can do is run a jumper from the battery positive to the coils positive. This will hotwire the bike, so only hook it up this way while you plan to ride. You won't be able to shut the bike off until the wire is pulled. But that will bypass all of the switches. Run it with the key on and kill switch on. If that fixes the problem and the problem comes back when you pull off the wire, then the problem is a bad switch or connector.

I should also mention, if the problem is something shorting out, you will have bypassed the fuses, so if you really want to be safe, you should put a 20A fuse inline with the test wire.

loudhvx wrote: I would first suspect a faulty ignition or kill switch contact. One test you can do is run a jumper from the battery positive to the coils positive. This will hotwire the bike, so only hook it up this way while you plan to ride. You won't be able to shut the bike off until the wire is pulled. But that will bypass all of the switches. Run it with the key on and kill switch on. If that fixes the problem and the problem comes back when you pull off the wire, then the problem is a bad switch or connector.

I should also mention, if the problem is something shorting out, you will have bypassed the fuses, so if you really want to be safe, you should put a 20A fuse inline with the test wire.

Now will hotwiring the ignition this way possibly correct my specific problem??

Just for clarification, I only have this bog/low power problem above 5k rpm specifically. The bike starts perfectly fine and has zero running issues until the 5k mark.

Also, I pulled off the ignition pickup plate just now, and I noticed that the top magnet is broken on the left side. All of the pieces are still there, but it's definitely cracked. Is it possible this could've happened while riding?? It doesn't look like the pickup plate has ever been taken off before. I don't see that affecting the running condition above a specific RPM, rather I could see that affecting the entire rpm range.

I would assume that a weak reg/rec would affect the entire rpm range as well, right?

Also, did a quick check over all wiring, nothing exposed or seemingly loose.

@loudhvx I read your webpage about the electronic pickups, im gonna check the polarity when I get home as well

Sorry for my repeat replies guys, but I have an update.

Just got home from work, and it ran perfectly fine the whole way across all rpm.

I have no idea what was loose or what, but whatever it was it must have gotten sorted out while I was poking around.

Still need to address the cracked magnets and I definitely need a new battery. I'm going to do all the electrical tests another day since it got me home and I've got the next two days free.

Thank you everyone for your suggestions and comments I appreciate you all very much, and I'll update this thread if anything strange turns up

I'm glad you are up and running but it isn't often and intermittent problem goes away and stays away. Your theory about moving something may well be correct in that you may have moved the oxidized contacts on one of many connectors. There is a spray product called Deoxit that removes the oxidation from connecters without damaging the surface of the connectors.

All those places Loudhvx pointed you to should be separated and sprayed with Deoxit, then blown dry with compressed air. As a quick check you should turn on the ignition and check the voltage at your coils. You are looking for something very near or north of 12V.

Hotwiring was just to determine if it was a wiring issue or not. But being intermittent, it is much more difficult to nail down. As Firehawk said, it's usually just a matter of time till it comes back.

Because it was so RPM specific, I would suspect the ignition switch before anything. That area, for whatever reason, seems to vibrate a lot on the 550's, or at least on the 81 Gpz 550. I assume it would be similar on the 82/83. But it can vibrate elsewhere, and it could be non-vibration related too of course.

I've seen a few bad solder joints on 550 ignition switches, but often the contacts are just worn out. On a re-wire I usually reconfigure the switch so that 2 or 3 sets of contacts work in parallel. (That disables the parking light feature, though.)

For now, if it was my bike, I'd wire up a jumper like I described, then leave out the fuse. When the problem returns, I'd pop the fuse in without turning off any switches etc, and see if the problem immediately goes away. (I suppose a hidden switch would do the same thing and might be easier to flip than installing a fuse.)

I realize not everyone has the supplies and tools necessary to whip this together. I guess it's what I'd do because it's what i have access to easily.

Regarding the magnets... you can use a broken magnet as long as it all goes back together the way it should be, like a puzzle, and as long as it will stay in place. It won't want to . A broken magnet wants to fly apart. The fact that it's broken won't matter, electrically as long as it is held together mechanically. Every magnet out there wants to blow apart into a billion pieces, but is held together by the mechanical properties of the magnet itself. As long as it's held together in the intended shape, the magnetism will stay oriented as intended with the same potency . That is assuming whatever broke it didn't weaken the magnetism. Hitting a magnet can weaken it, but if it broke from the screws being too tight or something like that, then it's probably fine.

And as you already read, the polarity matters as well as which screws are used where, as detailed on that page.