Help! My bike has lost its mind!

1984 Honda Sabre VF700S

I'm in need of some help here.

First off, can someone tell me where the ground points are on this bike so I can give them a good looking over?

Secondly, here is the issue:

My bike has lost its mind, something electrical is causing some serious problems. The bike has been running absolutely fantastic, rode to work, stopped at the gate to use the card lock, turned off the engine while doing so, then couldn't get the damn thing to start up again for a good 3-4 minutes, turned over, NEVER even tried to catch, then suddenly it started right up after many tires, as if it had no problems at all.

After this, I rode the bike around the parking lot for a few minutes, kept the RPMs up a bit and tried to make sure the battery was going to be OK to sit until going home, as I'm parking it, I'm noticing that all of the lights are cutting in and out and that the LCD indicator can't decide what gear I'm in exactly, the number flashing sometimes.

Many hours of work later, I'm ready to go home, the bike starts the instant I push the button, but the lights are still flashing, sort of getting a strobe effect from the headlight and the N on the LCD is there one moment, gone the next, I ride the bike home, its a nightmare, it cuts out randomly, I stop at a stop light after the freeway, a block from home, the LCD starts just sort of going off to lala-land and displays what ever number it feels like for a few seconds, then goes back to intermittently flashing the gear I'm actually in. It gets worse, I come to a stop, the tach is at 6K, the bike is running on *ONE* cyl and I've got to hold it between half throttle and WOT to get it to continue to idle, car in front of me, car behind me, moments before the light turns green, bike revs out and runs fine!

For it being only the third day I've had my full motorcycle license, I don't think I handled it too bad, but I have to wonder...

Is my bike trying to kill me?

I'd love to fix whatever might be the problem as soon as humanly possible, if its a part I can replace with simple tools and get at the local napa/autozone/kragen/etc down the block, let me know, I really need this bike to be running.

Thanks for any advice you might have.

 

your right .its possessed......... try looking at the main harness, check for a grounding issue your grounds should be clean and attached to the frame...then look for any wires that are frayed ofr cut through,.... its time consuming but thats where you should start...

 

Think I found the issue, I got the Clymers out and REALLY took a good look since vehicle electrical is the bane of my existence, found the main ground from the battery terminal that goes up under the tank, unbolted the tank and lifted it up (cant figure out how to get the tank off yet!?) and there it was, ground wire, bolt. I turned the ignition, lights came on, I grabbed the wire, and jiggled it a little, all the lights went insane, the damn bolt going to it is hardly what you'd call tight.

Got a big THICK 24" ground wire at autozone which I'll try to replace it with, if I can figure out how in the heck to get the tank up high enough to actually get at the bolt.

 

congrats.....lift and pull I recon

 

acctually it appears that its three bolts... two in the front and one in the rear....

1984 Honda VF700S SABRE OEM Parts, 1984 Honda VF700S SABRE OEM Motorcycle Parts - BikeBandit.com

 

I sorta gave up on taking the tank off after finding out about those other bolts, its a FULL tank, the bike wouldn't run well enough to ride anywhere to use the tank up, and I live in an apartment complex that would probably not look too kindly to someone draining a gas tank in the back parking lot, then taking it apart.

My solution!

Go to autozone, buy a big beefy ground wire of a decent length, bolt it to the battery, and find another bolt on the bike to put the other end on!

What I did:



Big bolt going through the top of the frame, top mount of the rear shock, took the nut off the end, slipped the other end of the ground wire onto it since it was a clean metal contact on the inside of that surface, put the nut back on, made sure it was DAMN TIGHT like it was when I took it off, then started the bike up, magic, all the lights are on solid, all is once again well with the world.

Anyone see any problems with this solution, or will this be good enough you think?

 

Went for a ride, but the problem was still there off and on, when I put the new ground wire in as per the picture above, I could jiggle the old loose one around as much as I wanted without any effect, went, rode the bike, and right as I was getting ready to pull in and stop, it started doing the same things. I took the seat off, jiggled the old ground wire and all the lights went nuts, what gives!? I figured I could just give it one big beefy ground wire and leave the other one loose for now, why the hell is it doing this!?

 

If it does it when you wiggle your original ground then I would say the simplest place to start is figure out how to get to that thing and tighten it up. It sure sounds like you located the problem. tighten it and take that piece out of the equation.

 

also ck the positive feed to the starter to make sure that is not loose.
also find org ground and fix that.

 

Well I had this on my Vf1000, the Regulator diode was letting A/c into the charging system
To test you need a voltmeter, run the bike check the volts on the a/c setting . Then replace the regulator. the ground or lack of it has fried it . My cents. have fun with this crazy hobby..Mike R..

 

Well, I went out and got some more tools to take care of it, managed to get the totally full tank of gas moved around just enough to get to the ground wire under it on the right side, the main ground had a second ground that was a green wire attached to it, I think this is the ground for some of the lighting and display up front. I took the big 4 gauge ground I installed and put all three of them together on the bolt under the tank, problem seems to have gone away, very slight flicker if the RPM's drop below 1k but it might very well have done that since I got it, never rode it at night.

I bought a voltage regulator just in case, its from an 1100 but I'd bet the wires are much the same. If the regulator starts acting funky, I'll see about replacing it, until then, I'm riding once again until the rain comes!

 

Good work!
Why do the work in a carpark. Find a ground floor unit and stick it in the lounge room on it's centre stand. LOL