04 xb12r running terrible

[RyanPeter]

After installing a voltage regulator, my bike started and is running like I have some serious problems going on with my fuel mapping or ecm programming. I have absolutely no idea where to start looking for my problem.

I have yet to put 50 miles on the bike, and was running fine until it just wouldnt start, because of the starter losing its ground. Fixed that by cleaning off the grounding points where the motor and sub frame meet the frame.

Then 10 miles later, the bike was unable to start because of a lack of voltage required to start it. 10.24 volts. So I charged battery for a few minutes and tried making it home, bike began to run like crap(misfiring, hard to shift gears, etc) until I pulled off. Hauled bike home and decided by similar issues of others on this forum that my voltage regulator needed replacing.

Got the part and replaced without actually diagnosing the problem like I should have done.

I have the downloaded service manual. I am just at the point now, where I dont have the time to work on the bike and will probably just bring it in to the dealership.

May my problem just be fouled plugs or something easy I can diagnose? Or did I mess things up by trying to make it home, with bike running all goofy?

The bike started with lots of black smoke and when given throttle, was really suffering to gain rpm. I don't know how else to explain how terrible it was running.

Thanks, Ryan

[Bullxb12r]

Are there any mods done? (aftermarket pipe, race ecm, breather, etc..) Generally black smoke is a good indication it's running too rich. If this is the case, your plugs may very well be fouled (or close). A little more info may be able to help diagnose better. As far as the charging problem, are you sure it was the rectifier (regulator)? try testing the stator also.

[ich]

fix the voltage problem first before touching the ecm. usually vr do not die at xb models. more common faults are a melted connector 77 or broken/shorted stator wires. check stator as described in the service manual. if you are going to buy a stator s/h, take care to get a 3 phased one, not the 2008+ two phased.

[jimijeans]

Ryan,As long as you have some time, there are some easy (but takes time)ways to check the items on your bike.1st Voltage, easy to just put a simple Harbor Freight OR Sears Digital Multi meter.SAVE your directions for use. I don't know the extent of your abilties for these problems. Always Do the Voltage check 1st.Set the meter to at least[20 V]OR higher.After bike is hopefully idling,Volts=12.6 and as the rpms climb so will the voltage.Max Volts is 14.6-have a load test done on bikes battery(auto parts)should be able to do that.The Grounds and Terminals are Touchy on these Bikes.The Plugs should be next.OK- is there any modifications done to the bike? What year & make is it?post up when can.`Jimi

[RyanPeter]

Ok. I called the previous owner and the only aftermarket part on the bike is the exhaust. Not sure the brand. He mentioned how he doesn't understand why I am having such an issue with the bike, because it ran fine when he sold it to me. Minus the voltage/grounding problem he thought he had told me about but actually never did. Until I called him and asked if he ever had trouble starting the bike. "oh, I thought I told you about that" No sir, you didn't.

Anyway, it is an 2004 XB12R with 26,000 miles.

[RyanPeter]

Tried starting the bike this morning, to do some voltage readings.
It doesn't start. Battery voltage is good, and cranks over just fine. Ok, I'm lost!

[GW 04 XB12R]

does it sound like it's running on one cylinder? you mentioned
The bike started with lots of black smoke and when given throttle, was really suffering to gain rpm. I don't know how else to explain how terrible it was running.

This could well be 1 or 2 fouled plug(s). I'd swap them out.

[buellbradski]

id try plugs sounds like one was fouled then if you were starting up n shuting right back down fouled out the other.

[RyanPeter]

Fouled plugs IS the problem. THANKS!!!!!