I recently bought a 1999 F4 with ~26K miles on it. The other day, the bike just quit, wouldn't get a spark, wouldn't start, and eventually (~2,3 minutes) all lights went out. Now, the person I bought it from just put a new battery in the thing this year. Its still got the original stator and voltage R/R.

When I took a battery pack to the bike, it started up just fine and ran good for a while. Now after about 15 ish minutes of idling the voltage regulator got incredibly hot. It was pretty warm today (85ish here in Newport, RI) and the heatsink on the R/R was noticeably warmer than the ambient temperature by quite a margin. Once I took the battery pack off the bike, the bike lost all power.

I then took a multimeter to everything I could think of. And here is what I found:

1) Voltage across the battery with the battery pack on: ~12Vdc
2) Voltage across the battery with the battery pack off and the regulator NOT hot: ~13Vdc
3) Voltage across the battery with the battery pack off and the regulator hot: ~18Vdc
4) Voltage out of the stator (I am pretty sure it is the stator) ~12Vac.
5) I did not notice a short to ground.

So does anyone have an idea what my problem would be? I am going to replace the battery because it cannot hold a charge anyways, but what could be causing my problem? I am thinking stator or voltage Regulator/Recitfier....

 

When you say it wouldn't start - are you meaning the starter wasn't kicking over, or the bike was turning over, but not starting. I'm dealing with an issue close to yours. Mine runs rough especially at idle. It's power related. I've done battery and rectifier so far - but found out that it's possibly not either. I'm going to be doing some more testing tomorrow I hope. What voltage do you get at the battery with the bike off and no battery pack?

 

Do you have a service manual? There are links here on the forum for the pdf version of the factory Honda service manual . Use the troubleshooting procedures to help diagnose the problem.

IF you've tested the battery & its no good, replace & re-evaluate.

IF after new battery & testing, the R/R turns out to be bad, here's some info for you...

The orig factory F4 R/R is an inferior design prone to overheating. The flat surface of the exterior of the orig fact R/R didn't allow for proper heat dissipation. Honda corrected that w/a new revised model that supersedes the old version. It is a really nice R/R w/ cooling fins. If you were to go to a factory Honda shop for replacement, the new version is what would replace it. I've written about the new version R/R at length here, giving part numbers, etc. You should be able to find those posts w/ quick searches. IF the rest of the bike is - as it should be - the new version Honda factory R/R will perform beautifully & be more than sufficient.

I'm meticulous about maintenance & ride all year long - daily commuting, weekend twisity rides, & track...in temps ranging from 50s to low 100s. I run the new version R/R on my F4. Since replacing my old version R/R w/ the new finned factory R/R, I've had absolutely no problems whatsoever. Again, if the rest of the bike is - as it should be - the new version R/R will give excellent performance.

As for the stator... Keep in mind that stators are generally very reliable on the F4. It typically takes some sort of impact to the stator to cause problems. Not that the stator can't develop problems on its own but its rare w/o some underlying cause - like an impact, hard drop, etc.

Hope your able to identify your issues & solve them quickly.

 

Stampern: Basically the battery is dead. Roughly 0V across battery without battery pack. I was pushing the starter button with nothing happening. However once I shut the battery pack off with the engine running, the bike idled terribly rough. Turn the battery pack back on and it ran fine.

gotcbr: I will be replacing the battery because I know thats shot (wont hold a charge). Ill try replacing the R/R as well. I suspect that something caused the battery to die as the battery was bought back in April.

 

Gotcbr: the problem was fixed by replacing the RR. Before I replaced it, I had 18v across the battery. After replacing, I had 14 which is what the regulator should be capping the voltage at based on some googling that I did.

Thanks for the help.

 

Excellent! Glad you're up & running.

 

So my electrical issues continue .....

The previous issue has been fixed.... Now I have a wierd issue with the bike shutting off and not starting.

Here is what happened:

I was riding around and all of a sudden the bike shuts off. I was in 6th gear going about 45 MPH and I did not hit the kill switch, put down the kickstand (Why you would do that at speed, idk) or turn off the ignition. I was unable to start the bike back up using the starter. Once I coasted to a stop, I pulled off the seat and checked the battery voltage (13V) so the battery is fine. I managed to pop start the bike and then I put the bike in neutral, put the stand down and leaned it on the stand and the thing shut off again. I pop started it again and rode it home.

Once I got it home, I pulled the seat off again and checked the fuses, nothing was blown. Before I put the seat back on, I could sucessfully use the starter. Once I put the seat back on, I couldn't use the starter.

I am thinking there is a short or loose wire somewhere between the right handgrip and the ECU or something. Either the killswitch is always on (though I wouldnt be able to pop start it...) or the starter (which wouldn't cause the bike to die when riding it).

Anyone got any ideas?

 

Not saying this is the problem but the starter switches can go bad causing all sorts of mayhem. Spray some wd40 into it & work it a bit.

Then, there's the starter relay & electrical connections. Check them all.

The kickstand switch can be a trigger for problems as well. Clean it off & soak it in wd40 as well.

Be sure to reference the factory service manual troubleshooting procedures as well.

 

I did find a slightly blown fuse on the starter line. I replaced and it work till it blew again. Ill try the wd40 on the stuff and see what happens.

 

i had the same prob with my 2000 f4,didnt know much about it then,so i threw$$$$$$$$ at the problem,r/r ,stator,relays,new fuel pump because the charging prob affects fuel pump operation,turns out it was a crushed wire in the harness under the seat...the little red plug next to your battery,plugs in the top,got bent n wouldnt make a proper connection,check the wire harness under seat,untape it,inspect the wires......might just b your problem...