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Discussion Starter · #1 ·
Ok, so I was wondering of some people could help me diagnose a problem that has started to form on my bike. Ever morning when I go to start the bike, it sounds as if the fuel pump has low voltage. Also, the same day, my Speedo/LCD screen along with my head lights started to flicker when I parked my bike.

I have installed the Tac to mpg gauge that was designed for the bike, its really the only electrical work I have done.

Some thoughts of what I think it could be.. but want your opinion.
Rectifier could be going?
battery could be failing (brand new though)?
Generator might be going?

Any thoughts?
 

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Does the motor crank over at a normal rate when starting? You can easily check on the charging system. If you can, charge the battery fully. Then meter the voltage at the battery for the following conditions:
At rest= 12.5-13VDC
Ignition on= slowly dropping to ~12V
While cranking= dropping no lower than high 10s
While idling= at least 13V
At 5Krpm= 13.5-15V
You can also check the output of the stator. Do you have a manual?
 

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Discussion Starter · #3 ·
Does the motor crank over at a normal rate when starting? You can easily check on the charging system. If you can, charge the battery fully. Then meter the voltage at the battery for the following conditions:
At rest= 12.5-13VDC
Ignition on= slowly dropping to ~12V
While cranking= dropping no lower than high 10s
While idling= at least 13V
At 5Krpm= 13.5-15V
You can also check the output of the stator. Do you have a manual?
The engine seems to crank over at the same rate when ever i turn it on. I do have the manual and Ill check those voltages tomorrow.
 

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The engine seems to crank over at the same rate when ever i turn it on...
Strong cranking means the battery is healthy. Flicker headlights means there is a flaky connection somewhere; might be the "dreaded green connector". <- Nice photos in that thread. Starter motor current does not pass through ole greenie.

Good idea to check the battery terminals also. Clean, then torque down with a 10mm socket, don't use a screwdriver.
 

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Discussion Starter · #5 ·
Strong cranking means the battery is healthy. Flicker headlights means there is a flaky connection somewhere; might be the "dreaded green connector". <- Nice photos in that thread. Starter motor current does not pass through ole greenie.

Good idea to check the battery terminals also. Clean, then torque down with a 10mm socket, don't use a screwdriver.
Would that also explain why the fuel pump sounds under powered at start up?
 

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When you turn on your ignition and the fuel pump primes, I believe the sound that you hear is actually the pressure regulator, not the pump. Not sure that you can sense whether the pump is getting the proper power or not.
 

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Would that also explain why the fuel pump sounds under powered at start up?
It might. The fuel pump draws about 4 amps, so doesn't take much resistance in a flaky connection to cause significant voltage drop. Even 1/2 ohm will drop 2 volts. On the other hand, if the green connector is 1/2 ohm constant, then it will burn up in no time considering how much current is passes...

Did the flaky LCD, headlights and anemic pump all start at the same time? If the weak pump sound is intermittent, it would makes sense.

I would start with the voltage checks RMAN suggested; if nothing is obvious, it is not too hard to lift the tank/airbox and inspect the connector.

You might also try direct measure of the pump supply voltage by back-probing at the fuel pump relay, Yellow/Red wire is switched power to the pump. If you do this, take care not to short anything while probing; there have been a couple cases where folks might have burned the ECM pump relay control output by accidental short. Good luck.
 

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Discussion Starter · #8 ·
Found the issue... did a quick one over on all the connections and found that the only one lose was the negative on the battery.... Ya I feel dumb right now :(
 

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:thumbsup:
Glad you got it fixed, Ochosi. Don't feel bad, we've all been there. ;D
 
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