91 vfr750 problems

Hey everyone I'm new to the forum and loving all the great content.

So here's what happened... After accidentally leaving the key in the on position for about 4 hours I drained the battery completely leaving me stranded (bone head move I know). I was able to bump start the bike and get on my way. While accelerating the bike feels like its bogging down for a few seconds and then all the power kicks in at once and accelerates hard. After a 20 min ride on the freeway the bike died at idle while sitting on the off ramp. The battery took zero charge from the ride but fortunately I was right next to an auto shop. They gave me a jump and I rode the rest of the way home (about 5 min). In that 5 min ride the battery took a charge as the headlights and dash lights stayed on after I cut the engine. Also the bike felt a little jerky accelerating from a dead stop and I had to give it more gas to compensate.


Any ideas what the problem is? The battery is about 3 months old, never had a problem. Is it possible that I did some damage with the bump start?

 

Start here read post # 9 you will find out what is wrong

http://vfrworld.com/forums/showthread.php/39277-How-to-fix-common-regulator-Stator-failures

 

Hi, welcome to our world.

Give the battery a good charge with a charger, not just by riding it. If it won't hold a charge or fully charge, you may have killed it. If a battery is drained too far, it might not come back to life, but that is usually only after being left under 9-10 volts for a longer time. You didn't do that, so I expect your battery will come back OK.

Then, use a voltmeter to check battery voltage while running at idle, then up to 5000 RPM. You should see 12.5-13 volts all the way up to 14-14.5 volts. If not, you may have fried your Regulator/Rectifier (common problem on the older Honda's).

Check your 3 yellow wire plug under the right side fairing for signs of heat and melting. Is it discoloured? Regardless, you should do the 3 yellow wire fix (cut out the plug and solder, then insulate the wires individually).

Let us know how it goes.

Cheers,
Glenn

Do what Norm said. :semi-twins:

 

Not me mind you, someone left the key on a MV Agusta (old one) and the coil melted and exploded all over the frame of the bike. Above checks are the way to start, could check for spark if all checks out with your r/r and stator. Invest in a new battery.

 

I would assume the MV had points ignition and sitting with the ignition on and the points closed will cook the coil. I think with these bikes with the ignition on it is probably only a small current drain through the ignition module. Doing the Drill is the only way to be sure

 

Your a sharp cookie ^ :thumbsup:

 

Running the bike on the dead battery can be damaging. The battery normally has some impedance but when it reaches a certain low level it acts like a short circuit. This stresses the charging components. A new battery or battery charge is the way to go here. Of course none of us learn this until after we've done the same thing in a desperate attempt to get home.

 

Thanks for the feedback. I'll check the charging system tomorrow and post my findings. Does a bad stator explain the acceleration problem?

 

I suspect you're low/dead battery did not make enough voltage for good spark from the coils. At low revs, still not enough, higher revs = higher voltage output = proper spark and power.