Hey folks, i was riding home from work today and looked down at my tach and saw it jumping up and down + or - 500 rpm around the actual engine speed, the speedo was doing something similar, i thought it was a bit odd and thought id look into it tonight, i then attempted to power through a corner and the bike lost all power, letting off restored the regular engine sound but any gas and it started to stall again, i limped it along until i found a safe stopping point, when i pulled the clutch she died, not even enough power to light up the neutral light, 10 minutes of waiting got it to barely turn over, i trailered it home.

Luckily i have a trickle charger and a clymers manual, i charged it for an hour at which point it fired right up, the battery voltage key off is about 12.4, key on 11.9ish, running at 1200+-100 i get about 12.8, 5k is 14.5ish. I rode it around a few blocks pretty hard, got it back and its idle voltage is 12.8 still. Battery is 12 months old, r/r is unknown age, 12 months old when i got it used, its a gsxr750 r/r.

What the hell is happening? Everything seems so normal but im not about the ride it 40 miles to work through the booneys again tomorrow without some closure. Any ideas? Sorry for the novel

 

Start by checking the stator. You should be getting 14/15v AC at idle and 30-50v AC at 5k Rpm on any pair of the three wires/legs....and they should all match.

If you have that, then likely it's a failing R/R.

Be aware too that one often causes the other to fail.

 

Ill try and check the stator after work, im also going to run the battery to the shop and have it tested, just seems weird that it would all the sudden fail then start working again, an issue i forsee is my r/r is crimped on, the gsxr doesnt have a plug so its not going to want to come off, can i just slip a multimeter probe behind the crimp for the stator wires at the r/r or is there a better place to test it?

 

That's fine.

 

Ok so i oredered a new r/r today preparing to replace it, however, i take a look at the current one and like i said its wires are crimped together...except one, one yellow stator wire had been knocked loose from its crimp, reconnected and im back at 13.5 volts at idle and 14.5-15 at 5k, battery voltage is coming back up also, im a little curious why with a disconnected wire i was able to obtain 14v? Wouldnt that charge it?

 

It's 3 phase AC , it's possible that it cant support a full load with one phase down.

 

So turns out i was wrong, riding home today the bike died again in the same spot it died last time, what was wierd was i waited 10 minutes and i barely turned over but did fire up and i rode it all the way home, turned it off and it fired right back up, anyone ever had intermittent charging issues like this before? Im about to just replace every part in the charging system

 

The sounds like a failing R/R.

 

You sir were correct, it was the r/r again. For good measure i replaced the stator as well because i know how one can affect the other. I replaced the r/r and it ran great...for a day. Today it was a weak start but did fire, then i smelled rotten eggs while parking at work and thought maybe there was a natural gas leak, wouldnt start after work but i did push start it and it ran fine...for an hour. 10 minutes away from home i hear what sounded like a gunshot and my whole panel went out and all guages went to zero, no throttle response at all...for a second. Everything came back on but everytime i gave it gas..BOOM! And no guages. Finally it dies altogether on the side of the road, no lights or anything, rotten egg smell again, and i pushed it home. Got it back and i could hear the battery boiling under the seat, jumped it with the car and voltmetered it, charging at 22v from the r/r. Obviously its toast, as is the battery, it only holds 2v now with the key on, but to bring a long story to an end, what else did or could 22v kill on the bike? It does still start while connected to kumpers but im not running it anymore, the temp guage also jumped to hot with every boom.?

 

Oh wow, that's tough. Usually they fail (fry) and put out nothing. Hard to say on the 22v, that's enough to fry just about everything/anything rated for 13v.

I've had batteries literally explode out of the sides of cars so as hard as it may seem right now, you might have been lucky you still have your a$$.