Voltage fluctuation normal?

issdar

Registered
Hi all, I have been having problems with hesitation at constant throttle like my bike loses power and regains it. It does not have any hesitation or feel of power loss if you goose it kinda feels like may be electrical. I put a volt meter to the battery and whenever I apply additional current IE blinker, brake light etc I notice the voltage will fluctuate .10v Is this normal? I can also visible see the back light for odometer slightly go dim and if I turn key on with the blinker on I can hear the fuel pump whine fluctuate and its not a constant whine. I tried normalizing system up and taking the power commander out of the system same symptoms. Can anyone please help me its very annoying do these "symptoms happen on your bike or are they normal?

I have a 2006 Hayabusa with Full Yoshimura exhaust, K&N air filter, small airbox mod, pair valve mod, power commander 5, dyno tuned.
 
If it's the factory battery it's probably time to get a new one. The manual is full of simple troubleshooting steps for the electrical system. You obviously have a meter. Let us know how it turns out.

How often do you ride ? Is your idle set around 1150 ? Do you use a charger ?
 
Rob, I replaced the battery when I got the bike 8 or so months ago I want to say. Idle is set to around 1150rpm I ride just about every day but dont use a charger never needed it. I will go through manual maybe check my voltage regulator for issues.


If it's the factory battery it's probably time to get a new one. The manual is full of simple troubleshooting steps for the electrical system. You obviously have a meter. Let us know how it turns out.

How often do you ride ? Is your idle set around 1150 ? Do you use a charger ?
 
Pull the seat and measure voltage per the manual, around 5k you should have about 13.5 volts. If that is good, chances are the battery is loosing capacity. Make sure the battery is full, I had issues every year with my 05's battery. Even though is it supposed to be non-servicible, I had to add water on occasion to keep it full. I had good voltage, but not enough amps. What is that called, sulfication? Could be time for a new one.
 
Rob, I replaced the battery when I got the bike 8 or so months ago I want to say. Idle is set to around 1150rpm I ride just about every day but dont use a charger never needed it. I will go through manual maybe check my voltage regulator for issues.

No. That all sounds excellent. There have been problems with voltage regulator connectors. Typically a small fire. But make all those quick checks, but I'm thinking battery or charging system, because that battery should not be bothered with a turn signal. Anything that has been added is suspect. Best of luck.
 
I just checked the voltage at idle it's 15v! That seems way to high at 5k rpm it's 14.5v. Could this mean a bad voltage rectifier I also read the pickup coils on stator could be shorting. What do you think? I'm gonna try charging battery to see if it makes a difference I also have my old battery.


Pull the seat and measure voltage per the manual, around 5k you should have about 13.5 volts. If that is good, chances are the battery is loosing capacity. Make sure the battery is full, I had issues every year with my 05's battery. Even though is it supposed to be non-servicible, I had to add water on occasion to keep it full. I had good voltage, but not enough amps. What is that called, sulfication? Could be time for a new one.
 
ok I further tested the charging system I checked the resistance of the generator and its within spec. Also check rectifier and the voltage readings where in spec also. I disconnected the voltage rectifier, generator, and swapped the battery with old one. same symptom when I turn on key with bike not started and turn on blinker backlights go dim. Could there be a short somewhere I am stuck.
 
Here is a link that may help.

http://stsamuel.tripod.com/voltage_reg_trouble_shooting.pdf

I am not a mechanic, but I would hook up a volt meter to a circuit and take it for a ride. Watch the meter and see if voltage is changing at the same time as the surge. Try more then one circuit include the injectors.

Also check grounds my 07 was doing some flashing if lights or lights going dim. I found a bad ground on one of the connectors in the harness.


1ibandit
88 ZL1000, 07 KaBusa
Sent from my iPad using Tapatalk
 
I would definitely check grounds / returns. No add-ons ? You have a drain test you can do as well.
 
I did the battery leak test and it was well under 3ma and passed. I checked most of wiring harnesses 1 by one trying to narrow it down and same thing.
Rob, could you check your busa and turn on blink or hazard lights then turn key to on position can you hear the fuel pump whine fluctuate or is it constant? It would be HUGE help so I know its not just a normal thing
 
Well brother Grip It and Rip It, cause my Gen II doesn't have the little odo window but with the hazards on it did fluctuate. The fuel pump whine cycled with the lights.
 
Niceeee to know. So I can stop worrying about electrical system I guess for now Thanks again! Guess I will move onto taking fuel pump apart and flush the fuel filter and test resistance/clean fuel injectors. Thinking it could either be fuel system something is bad can hear fuel pump whine over engine maybe fuel filter clogged or line crimped?...or another possibility when I got it dyno tuned he didnt compensate for my small airbox mod because he asked me about it AFTER the tune and forgot to tell him before tune. If it all ends up being a bad tune Im gonna be PISSED that shiat aint cheap.
 
Niceeee to know. So I can stop worrying about electrical system I guess for now Thanks again! Guess I will move onto taking fuel pump apart and flush the fuel filter and test resistance/clean fuel injectors. Thinking it could either be fuel system something is bad can hear fuel pump whine over engine maybe fuel filter clogged or line crimped?...or another possibility when I got it dyno tuned he didnt compensate for my small airbox mod because he asked me about it AFTER the tune and forgot to tell him before tune. If it all ends up being a bad tune Im gonna be PISSED that shiat aint cheap.

If I understood you correctly; it should not have mattered if you told him or not. He tuned it on the dyno. But if he went out and grabbed a map off the internet, yes it would be a problem, because those tunes are ballpark and based on the mods.
 
Hmm that does make sense it wasn't a premade map. It was dyno tuned for the current mods. I'm gonna go through looking at vacuum lines to. What is interesting is that if there's no load on engine and I just hold throttle constant it doesn't seem to drop at all. I am all over the place I feel like a n00b :/
 
Just went through checking resistance and checks on connectors all good. checked vacuum lines everything looked good. So here is my thoughts fuel pump faulty, or ECU faulty, or clogged fuel filter, or small airbox mod producing surges at part throttle. What can I eliminate if I cant recognize problem with no load and no problem starting bike, or with full thorttle and idle?
 
You had it dyno tuned and now you're having this problem. If this is correcting my bike would be visiting that tuner again for a fix.
 
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