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Discussion Starter #1
Hi all,

I'm having problems with my RC51 SP1 and I'm hoping you guys can point me in the right direction on the possible cause. I put a new battery in about 6 weeks ago. All was fine until last weekend when I went to start it after not running it for about 5 days and the battery didnt have enough power to turn it over. I jump started it and ran it for a little while after and all was well. I started it up this past Wed and let it idle for a while and it was fine. Today I started it with no problem and went to the gas station. After getting gas it was the same problem, battery not strong enough to kick it over. Any ideas on what the problem could be?
 

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For starters, it could be bad battery, poor battery connections, stator coil, or rectifier/regulator.

Check the battery voltage level with the switch off. It should be 13 to 13.5V.
If it's less than 13V, then the battery is low, which could be a bad battery, loose or corroded battery connections, or charging system.

Crank the engine and measure the voltage at 4000 RPM, it should be 14 to 15V.
It should NOT be over 15.5V.
If you're not getting 14V or above, then it is probably charging system.

Switch off the engine and pull the alternator connector, then check each stator coil resistance, and each to ground.
All stator coils should be within spec. You should not get a coil whose resistance is too low or too high, and no continuity to ground.

If the stator coils check out, then it might the rectifier/regulator.

One thing to always keep in mind is, weather is the enemy of electrics.
Many electrical problems can be traced to tarnished/corroded contacts on electrical connectors, especially over time in humid weather.

Buy a tube of delectric tuneup grease (5 oz. tube will last forever) and poke a dab into every electrical connector you can lay a hand on.
It waterproofs the contacts, prevents corrosion, and also allows easier disconnection.

And lastly, check the idle speed of the engine. It should be 1300 RPM +/- 100 RPM.
If the idle is at 1100 RPM, it may not be charging the battery at idle.

On my VFR800, I found that at 1300 RPM, the alternator output is 13.5V, which will maintain the battery voltage at idle (not charge the battery, just maintain).

If the idle was set to 1100 RPM, the output dropped to 12V, which is not enough to maintain proper battery charge. The bike then is running off the battery.
If you get stuck in a traffic jam or situation where there is lengthy idling, the battery voltage may drop to 12V or less that will not maintain operation of the ECU.
In that case, the ECU may cease operating and the engine will stop running, and fail to crank.

I also found on my VFR800, that at even 1500 or 1800 RPM, the alternator output was at 14.7V, which is enough to charge the battery, even with high beam on.
 

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Discussion Starter #6
Ok I just fully charged the battery and started it up. When running and at idle and I touch the battery terminals with the voltage reader, it reads 14.4. When on but not running it reads 12.3.
 

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That battery appears to be the correct size, it must be undercharged, loose/corroded connection, or some reason why it is not putting out the amperage that it should.

You might check your voltage at idle and fast idle to see if the RR is working properly.
 

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Discussion Starter #11
I looked in the manual and did the current draw/leakage test.
I disconnected the negative side of the battery and touched the negative amplimeter cable to the negative battery post connector and the positive amplimeter cable to the batteries negative cable.It read 10.5 :(
 

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Discussion Starter #13
Thanks for the help. I think the 10.5 reading I'm getting when it is shut off means there is something drawing the battery. I'm trying to figure out what it is....
 

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Discussion Starter #14
I ended up taking the tail off (for the first time woohoo) and I started unplugging things one at a time and then testing if the volts dropped to zero (where they should be). The only thing in the tail that caused this was unplugging the "starter relay switch" (page 1-35 in manual). I'm not sure what this means? I've read that to find whats drawing the current, start unplugging things and see if you still get a current. I havent done anything in the nose yet, and I'm not even sure if I'm going in the right direction? Any help or direction would be greatly appreciated!
 

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Plug the starter relay and everything back on and use a 12V tester attached on the battery's negative terminal.
Check the three wires on the starter relay's connector which one is live.
Only the Red one should be live with your key switch OFF.

Is that the case?
 

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Ok.

Now use the 12V tester on the key switch connector. While the key is to OFF position, do you get power to any wires other than the red one?

I am assuming that your description above is accurate when you say that you narrowed down the leak to the starter relay. I mean, when you unplug the relay's red connector, with the three wires, the leak stops, correct?
 
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