Help! XB won't stay running...

[masher]

Hello, and thanks in advance for helping a noob! I've got an '05 XB9SX w/ about 5k miles on it. The other day I was cruising about 50mph and the bike sputtered and then the engine stopped. Would not start, could not hear fuel pump when turned on, but it was cranking the engine. Got it home and it started for a minute and then stopped. Put it on battery charger and it charged for quite a while before switching to trickle. Now when turned to the on position, the fuel pump is very faint sounding compared to what it used to be. Will start no problem, but dies after about a minute and the battery will take a short charge before trickle.

Here's what I've checked so far.

-Battery appears ok (~12.7V and does not drop off too much when sitting).
-When running, battery terminals read ~12.8V.
-Checked voltage regulator connector (77) for bad connection but everything looks nice and clean.
-Checked stator connector (46) to ground - no conductivity.
-Checked stator across pins 1-2, 1-3, 2-3 and all are about 0.2 so stator appears ok.

Can't really do the other tests in the service manual cuz the bike won't run at any rpm for long enough. [confused] So either it's the voltage regulator (how will I know unless I replace?) or I have no clue what is going on. Any thoughts?

 

[07Bolt]

Regulator test: Key turned on,engine off- check the pins 4 voltage; if there is some then replace regulator.

 

[masher]

Thanks for the quick response, but I'm a little confused. Do you mean that I should connect the 77 connector, turn on key, and check the 46 connector pins for voltage?

 

[07Bolt]

disconnect 46 plug; (46 plug is stator,engine-off=no stator)(77 plug goes to fuse/ground from regulator)probe all 77 pins for voltage. Also, check that the Main fuse (main-fuse= reg/batt pos) is not blown. If u find minimal damage, squirt some dielectic grease into reg connectors,that might aid the situation.

 

[07Bolt]

Shunt regulators are often (but not always) passive and simple, but always inefficient because they (essentially) dump the excess current not needed by the load. When the stator/engine/battery exceeds normal voltage output, the regulator discards it.

 

[07Bolt]

Your symptoms suggest that there is arcing somewhere in the charging system. i.e. melted plug connectors; frayed wires; short to ground.

 

[masher]

Ok, the voltage at 77 connector is 11.9 on the battery side (red/black) and 0 on the regulator side. Sounds like I need to start tracing down the charging system...

 

[flaya564]

I know this may be a stupid question but when you say short to ground, is that any wire shorting to metal or is that a specific area on the bike?

 

[07Bolt]

Any wire that is under load (has electricity flowing thru it), touching metal that is grounded. This creates a low-resistance escape path for a large amount of current.

 

[07Bolt]

Another test is the negative cable; Disconnect the neg cable from battery, Use multi-meter, VDC-neg lead 2 batt,pos lead to cable. Should have 0 voltage from cable.

 

[masher]

Negative cable test shows 12.3V. Sounds like there's definitely a short somewhere...

 

[07Bolt]

On my firebolt there is a ground screw underneath the frame, behind the rear cylinder. When I installed the pipe wrap, i had to lower the engine out of the frame. It must have yanked the bolt loose/even stripped it. There is a lot of build-up around the area which is likely the problem. The only way to get to it: remove the shock & fan; lower the engine again and fix the mount.

 

[fahren]

Maybe a silly question, but how old is your battery?

 

[masher]

The battery is a couple years old, but I can't see how it would be the culprit (of course, I've been surprised before).

 

[fahren]

Battery was just a thought.

But if you are searching for a short, it's a good idea to remove you headlight fuse if you have the key turned for any length of time. Just cuts way down on battery drain.
Good first places to look: the plug wires (chafing happens a lot);
the harness, where it comes around a bend near the neg. battery terminal. Others with more knowledge can pitch in and suggest other first areas to look at.

 

[07Bolt]

masher...sorry,but the bolt i was lookin at was only a strap bolt. not a ground one. back 2 step 1,,,[mad]