Diagnosis Help Needed Please

[Hypocycloid3]

Riding my '94 today.. leaving a stoplight, got to 3 gear maybe 40mph and everything does a total shut down immediately. No sputter & die. Just an immediate loss of all power. I roll to a stop cycle the ignition key and switch, power comes back on starts right back up revs feel fine. Get another 30 feet does the same thing. after a second or two able to turn off and back on again. Seems fine. Ride and make several stops over the course of the next 2 hours and travel about 15 miles in town. Just when I start thinking everything must now be okay.... bike does it again and this time I get nothing back.. no power to the headlight, no power to the green neutral light, no (buzzing) power to the fuel system / vboost servo and have to get towed home. Wiggled about every wire I can find while ignition is on to see if things suddenly come back to 12v life. all the obvious stuff seems fine... battery, gas etc. Gotta be electrical right? but I don't know where to go from the battery. If ignition switch wears out, it's not just gonna die while riding. right? What would do this,, Really hope its not the Ignition Unit Assembly. Seeing it listed for $900 on K&N Yamaha OEM Parts.

 

[KosRider]

Hypocycloid3,
take a look at both the ground cables from the battery. One - the smaller one - goes to the frame front and left of the battery. The second big one downs to the engine near the oil fill cap. Make sure both termanals and surfaces they butt up against are clean. But more importantly, peal / cut away the covering where the wires enter the terninals and solder these connections. Me thinks the smaller frame ground is dirty / corroded and not serving as a proper electrial ground leaving the big wire ground attached to the engine as the only operating ground.

Problem that I had on my 06 was that the copper wire and the terminal were only crimped together on this big ground. And when the engine gets really hot, the terminal crimp expands more than the wire and the ground connection is lost.

From what you're experiencing, if this was the only ground working... complete electrical shut down until the crimp connect cooled slightly to remake the ground wire connection. Riding a little bit more reheat this crimp connection to give you this reaccuring problem.

When I soldered all these, problem went away for me.

Good luck and let us know what you find !

Jeff

 

[Rollie]

Try switching fuel switch over to reserve .

 

[ninjaneer]

sounds a lot like what had happened to me last summer. it more than likely was a ground terminal that i found that had broken off of the frame nut on the right dide under the seat. i would mystically make the bike"work" again by jiggling the bike back and forth when shat more ghan likely happened was my knee pressing the seat that in turn pressed the terminal back in contact with the frame. after repairing it, haven't seen the intermittent problem agian....knock on wood

Regards from my Taptalking Hercules Android

 

[Miles Long]

Riding my '94 today.. leaving a stoplight, got to 3 gear maybe 40mph and everything does a total shut down immediately. No sputter & die. Just an immediate loss of all power. I roll to a stop cycle the ignition key and switch, power comes back on starts right back up revs feel fine. Get another 30 feet does the same thing. after a second or two able to turn off and back on again. Seems fine. Ride and make several stops over the course of the next 2 hours and travel about 15 miles in town. Just when I start thinking everything must now be okay.... bike does it again and this time I get nothing back.. no power to the headlight, no power to the green neutral light, no (buzzing) power to the fuel system / vboost servo and have to get towed home. Wiggled about every wire I can find while ignition is on to see if things suddenly come back to 12v life. all the obvious stuff seems fine... battery, gas etc. Gotta be electrical right? but I don't know where to go from the battery. If ignition switch wears out, it's not just gonna die while riding. right? What would do this,, Really hope its not the Ignition Unit Assembly. Seeing it listed for $900 on K&N Yamaha OEM Parts.

If it is a total loss of all power, and the battery and ground connections check out O.K., check the red power wire from the positive post to the ignition switch. This includes the main fuse and it's two connectors, and the three wire (red, blue and brown) ignition switch connector, which you will find between the headstock framework, after removing the faux tank. This connector has failed on several member's bikes, including mine. If all the connectors check out, clean them well and reassemble using di-electric grease. If still no power, disassemble and clean the ignition switch itself. Not a difficult job. There is a sticky in the "How-to" forum (or Electrical forum) with instructions.
Cheers!

 

[Hypocycloid3]

Okay Got It thanks to You Guys! Thanks to Kos and Ninja for a good place to start. Checked serviced and soldered both my grounds but no change. Miles, nailed it. Checked red wire continuity successfully at every connector all the way forward to the ignition connector which only left the ignition itself. Used the Sticky in How To Guides to recondition the ignition. (great write up with pix by Ninjaneer and others btw) Had to re-solder the red wire while in there.

 

[KosRider]

Way to go Miles !! You da man !! :clapping:
We'll have to start calling you the "Doctor House" of the VMax community !!:rofl_200:

 

[Miles Long]

Way to go Miles !! You da man !! :clapping:
We'll have to start calling you the "Doctor House" of the VMax community !!:rofl_200:

Thanks, Jeff. I really dig that Dr. House character.
But I think my paltry posts pale in comparison to what other members have contributed. I have learned much more than I have added.
Cheers!