About a month ago i bought a 2000CBR F4, when i bought it i had to put a new battery in because the one in it was dead. It has started fine every since i bought it, but this weekend i went to start it and it started really hard like the battery was almost dead. I rode it around for a while and shut it off. When i went to start it the next day i got nothing. I took the battery out and had oriely auto test the battery and they said it was good and they recharged it for me. I then took the bike and had the rectifier and charging system checked along with the battery one more time just in case and everything checked out good. So i am wondering if there is something drawing from the battery when it is shut off that it causing the battery to slowly drain over time. I know that the previous owner had the trun signals integrated into the tail light, i dont know if that would cause a draw on the battery even though the bike is shut off.
Thanks for the help
-Matt

 

You need to invest in a good electric multimeter.

Check 2 things. Voltage at idle/5k rev. It should be above 13.5v min.

Shut everything off, disconnect power wire. Hook meter up in series and check number of amps the bike is pulling with the key out.

 

I would look for stuff that that has been wired up onto the battery posts or close to it. Do a current draw check like stated above. If you find something then start unhooking things or pulling fuses and see where the draw is. I would do a current draw check on the starter as well, just for giggles.

 

I checked the voltage with the bike on and off and everything checked out ok. So i went to go for a ride last night and the bike started perfectly fine. I rode for about and hour and on the way home i stopped to get some gas and when i went to leave it was like the battery was completely dead. I would barely even turn over one crank. So i had to bump start the bike and rode it home. I let it sit for about 15 mins and started it again and it started fine.

The previous owner of the bike did try and integrate the turn signals into the tail light and im not sure if that is something that could be causing a short or draining the battery. I am stumped and not too sure what to do. It makes it pretty hard to ride when you are afraid to turn the bike off not knowing if its going to start or not.

Any ideas?

 

First I would check the ground to power side. If there is low resistance you may have a short. I would check all your light bulbs for proper security and or water that may cause the short. Look for corrosion on connectors as well this will cause a high resistance short. Personally if you had a short somewhere you would have seen it in your fuses, unless it was a high resistance short. High resistance shorts draw excess power without burning a fuse, and are mostly in the form of rust between pins/ frame. If you cannot find a short it may be the power supply side of the bike.
I had the similar problem. Burnt a battery. I changed my stator still same problem.
Common problem is the Volatage Regulator, the little box on underneath the rear fairing on the right side.
The volage regulator charges the battery and absorbs excess volatage (shunts voltage) it also supplys power from the alernator to the bike. Problem is when it shuts it gets very hot, and if its not properly cooled it will burn out. The one installed on the F4 is a small crappy one with no cooling fins.
If the Volage regulator is fried it will not recharge battery and acutally draw power from battery only. One way to check if your Voltage regulator is fried is to check the pins where the 3 yellow wires go into to each other if you have an "Open" or infinate ohms its fried. If you have some ohms, it would be safe to assum its good. I would presonally change it out anyway, because its only an amount of time that it will fry out.

There is a nice replacement one that actually has cooling fins on this sight: www.psep.biz/store/honda_motorcycle_voltage_regulator.htmr is AHAHA6017
It has a connector you can just plug into your harness. and you can put it on your frame with no modification. Not to mention it is like 70-80 bucks cheaper then oem.
I replaced mine with a F4i one but i had to crimp the wires. Keep yours original and get this regulator!

 

Just a little update,
I have not had time to check or replace anything furhter yet, hopefully this weekend. But last night i rode to a buddies place about 45 mins away and the bike started perfect and ran perfect. When i got there it was shut off for about 20 mins and when i went to leave it was dead once again. I bumb started it once again and rode the exact same distance back home. So i shut it off and let it sit for the same amount of time and went to start it and it started perfectly.

 

Sounds like a bad connection at your battery or starter relay.

 

yeah sound like a bad connection