Electrical Issue

[Hans2001max]

Hi,

Took my 2001 Max out yesterday and immediately some new problems cropped up....

The bike started shuddering and losing power like it was missing. Noticed the tach had jumped all the way to 9000 rpm and kept bouncing around that rpm . The engine was not going that fast (I couldn't!), as I was only doing 10 mph. Temp gauge appeared to quit working.

Hitting the brakes and clutch affected the tach, as I could see the tach needle move whenever I pushed in the clutch or used the brakes. Also, my blinkers quit working.....and you could see that affected the tach whenever you used the blinkers.

Eventually, the bike completely dies while moving. It restarts easily, and works fine, but after a few miles, I will start to see the tach jumping around, and then the same issues as described above come up again, ultimately resulting in the bike dying.

If I see the tach start jumping, followed by the power loss, I can shut the bike off, and restart it while moving, and it seems like it "resets" itself and everything is fine....until it happens again.

Some history....completely stock 2001 Max. I replaced the two front coils when I experienced a severe power loss and lost my tach. That fixed the issues.

Battery is a ney Odyssey PC680. Great battery.

I am really bummed out about this problem.

Any input on what you think and where to start looking would be appreciated.

Thanks

 

[jfeagins]

Check all ground wires for condition and tight fit. There's a cluster under the seat on the right side of the bike all attached to one screw to the frame - make sure that bunch is all clean/tight. Double check the big main battery ground wire at both ends too. After that, I'd start looking at all wire cluster connectors for fit/condition. Perhaps one inside the headlight shell is loose or corroding?

 

[davesax36]

Does one of those wires in the cluster control the CDI box? I've got everything needed for startup except spark...

@#$%

 

[bazwell]

Check all ground wires for condition and tight fit. There's a cluster under the seat on the right side of the bike all attached to one screw to the frame - make sure that bunch is all clean/tight. Double check the big main battery ground wire at both ends too. After that, I'd start looking at all wire cluster connectors for fit/condition. Perhaps one inside the headlight shell is loose or corroding?

+1
Bad earth is where I would be looking. Battery terminals, where the earth connects to frame and engine, and any connectors forward of the airbox.

 

[RaWarrior]

+1 for a bad ground somewhere. Current is barely flowing, it heats up the connection, and eventually the circuit starts getting interrupted and things start to wig out.

You have a digital ignition box, which tend to be very reliable but they're not infallible. TCI(transistor controlled ignition, as opposed to Capacitor Discharge Ignition) rely on a ground to work....coils are always energized, and the box completes the circuit to ground to fire them, (CDI works just the opposite). A poor ground will screw with the box and can cause all sorts of wacky problems.

The chassis ground was mentioned above, the main one is bolted to the engine just behind the oil fill cap. Even if it "looks" OK, remove the bolt, clean up the surface with a wire brush, and add a spot of dielectric for good measure.

I had a 4 stroke snowmobile with a similar problem, turned out to be a loose battery cable at the relay. It made the check engine light come on, it ran like crap, misfired, would stall out, ect.

 

[dingy]

You have a digital ignition box, which tend to be very reliable but they're not infallible. TCI(transistor controlled ignition, as opposed to Capacitor Discharge Ignition) rely on a ground to work....coils are always energized, and the box completes the circuit to ground to fire them, (CDI works just the opposite). A poor ground will screw with the box and can cause all sorts of wacky problems.

I am not trying to be a know it all here, but I have done some research into these ignition boxes and from what I know, all the VMax'x & the Venture box's are TCI units. The primary change in 1990 on both models was the went to a fully digital type circuitry with one pickup coil. With the 85-89 VMax's (& the 83-89 Ventures) had an analog based, but still solid state style system where there were actually 4 independent circuits in the TCI, one for each cylinder. As RAwarrior stated, a TCI based system normally is energized, the circuit is interrupted by the TCI at the instant of firing, which causes the coils field to collapse thus inducing a surge into the coil secondary and plug fires. A CDI system is basically opposite, in that it is normally deenergized and at instant of firing the coil is powered up & the surge builds the field in the coil causing the secondary to be energized and fire.

The firing/timing mechanism is fairly straightforward on the 4 pickup coil units. With two inducers on the flywheel, it would be easy to determine precise timing for each of the 4 cylinders

With one pickup coil and one inducer on the rotor, it is seemingly a little trickier. The first thing is this system forces the wasted spark concept where every plug fires every revolution. What is a little more complex is the difference in firing of the the firing order. 1-3-2-4. The single pickup may trigger #1 & #2 on the leading edge of the inducer passing the pickup coil, then fire #3 & #4 when the inducer clears the pickup coil and the field collapses, but this is a Wild Ass Guess.

Cut from the 85 service manual describing the TCI system.

Gary

 

[GREEN light BLITZ]

Had this happen once and leave me stranded...turns out the connector going into my main fuse had got a bad connection. (when we switched to the R6 r/r I only have one fuse with 2 female connectors to it)

SO what Im getting at is check your 30 amp main fuses...both of them. They are in the little black box by the lock for the faux tank.

If you have a continuity tester check them that way or just replace them both to be sure.

 

[Hans2001max]

Just thought I would post an update. Thanks for all the input. The issue was much simpler than what I thought it would be. I started tearing into the bike and moving around wires while it was running. Checked the areas that were recommended above but I couldn't find anything wrong. Bike was not mis-behaving when I moved the wires around in the areas where I had done some work before.

I started to get a bit bummed out when I wasn't finding any noticeable issues. But then, I tried re-starting the bike and it wouldn't start at all. I have a jumper cable with a pigtail hooked to the battery so I can charge the battery without having to take the seat off. It stays on the battery all the time. When I moved that around, the bike started up! I immediately ripped that jumper off the bike, and it solved the problem. Why that bad jumper would cause all those weird symtoms and the bike eventually shutting down is beyond me. But I am confident that was the issue, as I have put several hundred miles on it since then and it runs great. The interesting thing is that I cannot find a short in that jumper cable. I checked it with my voltmeter, and it doesn't show it as being shorted. Anyway, I know I am not putting that thing back on, though!

Thanks again for the responses.

 

[naughtyG]

Great to hear you found your problem! It can be really weird sometimes...

Example, after riding my bike for over a year, one day after a lot of riding at low speed in hot weather it refused to switch off. Whatever I did, turn the key, take it out, it would still run. Only way to stop the motor was the killswitch, but even then the lights etc stayed on. Only way to turn the juice off was to pull the main fuse! Renamed the bike 'Christine' at that point (ever seen the movie? lol)

Now, I'm pretty handy with electrics. I troubleshooted the whole bike, unplugged every single component, even went as far as unwrapping most of my wiring harness - to no avail.

In the end, I was lucky enough to have a spare harness of a parts bike of the same year, so I replaced the whole harness and that fixed it. To this day I have NO IDEA wtf happened!

 

[Geek_Law]

... Why that bad jumper would cause all those weird symtoms and the bike eventually shutting down is beyond me.

Last year my bike went totally nuts with those same kinds of symptoms, except once she died the dang battery was dead, despite being new and freshly charged.

Anyway, each time the bike got near death, it acted totally bonkers. RPMs showing weird readings all over the map ... blinkers stopped working. Just weird.

On mine it was the stator and rectifer which needed replacing, but it seems that once the power gets super low, those components just act nuts. I suspect they were starving for voltage due to your jumper and this was their way of telling you.

Anyway, glad you got it fixed.

 

[Miles Long]

Great to hear you found your problem! It can be really weird sometimes...

Example, after riding my bike for over a year, one day after a lot of riding at low speed in hot weather it refused to switch off. Whatever I did, turn the key, take it out, it would still run. Only way to stop the motor was the killswitch, but even then the lights etc stayed on. Only way to turn the juice off was to pull the main fuse! Renamed the bike 'Christine' at that point (ever seen the movie? lol)

Now, I'm pretty handy with electrics. I troubleshooted the whole bike, unplugged every single component, even went as far as unwrapping most of my wiring harness - to no avail.

In the end, I was lucky enough to have a spare harness of a parts bike of the same year, so I replaced the whole harness and that fixed it. To this day I have NO IDEA wtf happened!

I'm quite certain I know what happened, Mr. Naughty. Same thing that happened to me, and at least one other member of this forum. The ignition switch harness connector shorted out between the terminals.
If you still have your old harness, check out both parts of the connector for continuity. On my bike it was the female end of the connector that shorted thru the plastic, between the red and brown terminals.
Cheers!

 

[naughtyG]

I'm quite certain I know what happened, Mr. Naughty. Same thing that happened to me, and at least one other member of this forum. The ignition switch harness connector shorted out between the terminals.
If you still have your old harness, check out both parts of the connector for continuity. On my bike it was the female end of the connector that shorted thru the plastic, between the red and brown terminals.
Cheers!

Interesting - that would make sense! Don't have it or the bike anymore though I don't think - if it's still in FL I'll check it out next time I'm there! Would be great to know for sure :worthy:

 

[bazwell]

Glad you got it sorted. Maybe it will only show a short when twisted the right way, if you know what I mean.

Anyway, good work! :biglaugh: