Bike abruptly quit running

I am new to VFR ownership and love it so far. I have a 96 VFR 750 and tonight while out on a ride it died as if you turned off the key and would not start again. I was close enough to walk home and grab the truck and jumper cables. Hooked up the cables and the bike started right up. I took the cables off and it continued to run. Turned the key off and then tried to restart it and had no power. The battery is on a charger now but I have what may be a stupid question but here goes. Is the system on the bike like a car where it should run as long as the alternator is good despite the battery condition? If the battery is bad will the bike still run? In my mind I am thinking alternator but not sure at this time. Thanks for the help.

 

Alternator is fine if it continued to run, strange that it stopped while riding unless the revs dropped below the alt kicking in. Charge the battery, don't use a car battery charger they will kill a motorcycle battery, and check the ground connections to the frame, undo them, don't just look at them, remove, clean and reconnect. If still no go battery is suspect

 

I guess I should start by extending a welcome to the MadHouse:welcome:

When it comes to your bike troubles - you are not alone. Combine good weather and a public holiday in the States and sure enough we get another swarm of similar posts on the forum. Basically the charging system on your bike is not one of its strongest assets and they tend to go wrong with a period of extended use or heat... It looks like yours is the latest. Anyway this should help you find and hopefully fix whatever ails your particular bike.

http://vfrworld.com/forums/5th-gene...how-fix-common-regulator-stator-failures.html

Post up again if you are not sure of anything or need help understanding the results.

There are important differences between the charging systems on a bike and a car. This article covers some of the key elements, the important point being, that whilst its fine to jump start a bike by drawing on the battery of another 12 volt vehicle, their engine must NOT be running or you can fry the RR on your motorcycle in seconds. Jump Starting a Bike

Whilst you probably have plenty enough on your plate at the moment, it would be great if you can find time to post up a bit about you and a picture or two of your bike in the Introductions forum (click the icon two to the right of the envelope and follow the prompts.). Then head right to the top of the page and use the My Profile link to update your forum profile to include specs of your bike and a rough location - city/State is fine. That way if you hit problems and need help, you may find someone on here nearby willing to swing by and offer advice in exchange for some beer tokens.

Take care



SkiMad

 

Thanks for the help. I trickled charged the battery last night and installed it this morning. Bike fired right up and I rode it home 10 minutes without an issue. I am going to take and have the battery tested this morning to see if that is the culprit. If my RR is bad will the bike still run or not? I looked at a couple of my electrical connections that I can see without dismantling and none of them looked burned. Further investigation to follow.

 

You may have had a bad battery connection that you disturbed . Lots of things possible but start with the easy stuff, make sure the battery to frame connection is good,battery connections are good.If the battery is good then check with a meter what voltage is going into the battery. If that isn't right start thinking about the rec/reg but the fact it was obviously running on the alt means this could be ok, but it may also only be putting out enough voltage to tun the ignition not charge the battery as well

 

Thanks for the update - Dallas!

Even if the bike has a faulty RR, the bike may be able to run whilst there is enough power in the battery. But it really depends on what has gone wrong in the RR - failure of the regulator element could supply low or no volts, or worse still, it could supply serious (+60) over volts which will quickly boil/kill a battery, and blow headlights etc. Nothing will probably work if there is a direct short in the RR or the rectifier starts delivering AC volts to the wiring. The most regular connector to fail is where the three wires from the stator plug into the RR but as I don't have a 96 I cant say for sure but, if it was a 6th Gen then, you would not be able to see that connector without removing the fairing.

Its not worth jumping to conclusions. If you are lucky, the problem could be down to just a loose battery connection, or the battery is on its way out. But so you can have confidence the bike won't leave you stranded again, its well worth spending a few minutes more to check the basics whilst you have the multi-meter out.

Basically all four elements of the charging system (battery, RR, stator and loom) need to be in good health. A fault with any one can damage one or all of the others. The link in my earlier post explains "the drill" = what you need to do, to check for the most common charging system faults. As you will see, checking out the battery is indeed the vital first step. If you have no idea how old the battery is, then this may help you work out whether its time to replace the battery.

To test battery: (original Yuasa type) - remove from bike and trickle charge overnight with a decent Optimate type digital charger until it is fully charged. The digital chargers won't over charge/cook the battery. So next morning ...

- End of charge volts should be 12.7-13.2V
- Connect a load to the battery (any old 21W indicator bulb should provide enough drain)
- Check voltage every 30mins or so and see how long it takes for the battery volts to drop to 12.3V
- Less than half hour = Totally dead battery - bin it!
- About one hour = Virtually dead battery - needing replacement now!
- More than one hour 30 = battery is still serviceable - but will need replacing soon
- More than two hours = Good battery.

Assuming the battery is considered good or serviceable - put it back on the trickle charger and next morning hook it up so we can check the health of the stator and RR, by monitoring the volts at the battery. First at idle and at 5,000 rpm with the bike cold, and then after a 30 minute + ride, so the bike and everything electrical is good and hot. Sometimes the stator will work fine when cold, but as it heats up the windings insulation can fail, and start to drain the battery, not charge it. Normally a healthy stator and RR should be delivering 13 - 14 volts+ at idle and between 14 and 15 volts above 2,000 rpm. It should never exceed 15.5 volts or things like headlight bulbs will blow. (Lights on/lights off should make no more than about 0.5V difference to those numbers.)

Post up the results if anything looks wrong. Good luck.





SkiMad

 

Battery tested fine at the parts store up to a 300 load. Put it back in my bike started and checked with a meter. I am only getting 12.2 at idle and at 5000 rpms. I guess I have a bad stator. How difficult is the install for a new one?

 

Hold your horses - a few minutes more testing will confirm whether its RR or stator or both which need attention. Refer to the drill. Basically we need you to check the AC output from the stator. I don't know where the connectors are on a 96 but they will almost certainly be tucked behind the fairings which will need to be removed. Once the fairings are off, find that connector (the charred one in Rubo's post). Inspect it for signs of heat damage. If its fine, disconnect it and then start the bike (it will run for long enough on the battery without the RR connected). Set your multi-meter to AC volts and to a range which will handle up to 100 volts or similar, then test the volts across all three pairings of the wires (probably yellow?) coming from the stator. When testing take great care with the probes so you do not to either earth the stator wires to the frame or allow the probes to create a short between any of the wires or there will be a loud bang and you will definitely be buying a new stator (which will not be cheap!).

I am not sure of the specs for a 96 stator but you are looking for reasonably consistent numbers over 14 volts AC at idle and nearer 60 volts at 5,000 rpm show a healthy stator. If any pairing is well low or totally dead it is a definite sign it needs replacement. If the numbers are fine repeat the check as soon as possible after taking the bike for a good 30 minutes plus ride so the bike and wiring is good and hot. If numbers remain consistent as before, then the stator is good and suspicion points to the RR.

Hope that makes sense. You are nearly there so hang in there!




SkiMad

 

I did your test at the RR plug and had just over 15 volts at idle and 50 at 4000 rpm. It is running now to get everything hot (at 100 degrees it wont take long. Let you know what happens after that. Thanks again for sticking with me on this.

 

The bike ran about 5 minutes and the RR started smoking. Killed the bike and unplugged the wiring. Everything still looked good as far as the wiring goes.

 

Morning (Sadly its not "good morning" over here as its Sunday and its raining) which means I am sat at the PC not out on the VFR ...

Anyway - the initial stator numbers look OK, but as we did not get the running hot numbers - the stator is not completely in the clear yet.

Did you manage to carry out the static stator checks - as described in the post by Rubo (which I linked you to earlier)? If not can you do them now and post the results. (the bike does not need to be running)

• Get a Volt meter, charge the battery, let it rest for a couple of hours then check the voltage should be 12.7V or higher for a fully charged battery in good condition.
• Now disconnect the rectifier/regulator from the alternator, normally 3 yellow wires on a Honda, then set the meter to OHM's (resistance) then measure the resistance between each of the wires on the stator side plug. It should be less than 1 ohm & then measure each wire to earth, as in the frame of the bike or engine bolt, it should not read. If that checks out, then the stator is fine.

If those checks are good then chances are your stator is OK. If you really need to be certain - you could pull the stator cover and look directly at the stator for signs of fried windings - but you will need a new stator cover gasket to do that check. But I would not bother if the static checks are clear.

If it helps this is what my fried 6th gen stator looks like ... (the yellow bit is what it should all look like - the burnt black stuff is where windings have failed).




Meantime smoke from the RR confirms it is faulty. So you need to source a replacement RR. The OEM ones, if still available, were never great, but plug and play upgrade options on a 96 may be hard to find. If you intend keeping the bike long term then rather than buy/fit another OEM, the perfect option would be to upgrade and fit a Mosfet unit, as they run a lot cooler than a standard unit and will probably provide clean spike free DC volts for longer than you will own the bike. Shindengen FH020AA Mosfet Regulator/Rectifier They will not be a plug and play solution but if you can handle a soldering iron I see they now offer kits which will make the swap fairly easy.

Whilst you are waiting for the new unit to arrive please pull the fairing off and with an inspection lamp thoroughly check the charging loom for signs of burnt wiring or melted connectors, and ensure the earthing points and main 30amp fuse (by the battery) are not corroded or loose. Sadly on the early VFR's Honda opted for some pretty thin wiring which struggles to handle the load especially when its hot. If you find anything worrying there is an add on wiring kit called something like a VFRNess? (a search on here should find more info) which you may want to investigate as a way to upgrade at least the main charging circuits of the wiring loom. Thankfully by the time they got to the 6th gen they figured to use better wiring.

Nearly there hopefully...




SkiMad

 

I did do the test on the yellow wires and they were all good. Out of my service manual I also did a charging coil test which was good s well. The final test out of the manual was to test across the RR which the values did not register as they were supposed to. So it looks as though the stator is good except for the in ability to check it with the bike hot. I have all fairings front and rear off the bike and all of my wiring is still soft and pliable and each connector I unplugged and they look new. I will order a new RR Monday and see what happens. Thanks

 

The new Mosfet RR arrived today and the install was a piece of cake. I had to drill two holes in the existing plate that the old RR was mounted and bolt the new one on. Crimp 3 wires, attach the pre-made battery cables and voila! The system at idle is now putting out 12.9 at idle and 14.4 at 5000 RPM. I took it for a 30 minute ride and got the heat up on the wires and stator. Upon returning the voltage output was the same. I also went ahead and bought a new battery due to not knowing how old the other one was. Jack over at roadstercycle was great and even called to make sure I understood the install after he shipped my part. I also purchased from him an LED volt meter that simply hooks to the ignition or running and grounds to the frame and will change colors if the system begins to lose voltage. Thanks again for everyone input and help with this. You guys saved me some cash!

 

Result - Thanks for the update:thumb:.

Now get out and enjoy your bike before the weather goes south...


SkiMad