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06 750 charging issues

1482 Views 6 Replies 3 Participants Last post by  SilverAthlon
Hoping to get some insight here. 13.3k on the odometer.
New Rick's MOSFET RR in 2017 around 11k, the OEM one literally burned itself up.

Late 2019 (September) the bike suddenly died at 75mph, leaving me to quickly cross 4 lanes of rush hour traffic on interstate, to the side of the road on way home from work, gauges lost power, couldn't push start, etc. Seemed similar to problems from 2017, a new battery (old AGM was 5 years old seemed plausible at the time) only stranded me again on the way home. Sheepishly trailered home, put it up on jack stands and considered options all winter.

I decided based (on odds?) it was the stator, and ordered Rick's stator to have on hand after the winter thaw. Enter Covid-19

I drained oil and took off the stator cover, what I saw wasnt what everyone else has posted over the years - black/burned areas on the stator. 2 splines (or whatever) were slightly darkened at best no obvious signs of issue though. I did get 13k out of it, seems well enough.

Followed service manual to reassemble with new Ricks stator, cover gasket, and tested voltage across battery, still ~12v at idle and 5k rpm.
I was not surprised to hear the stator whine, only making it all worse.

I followed all the service manual electric troubleshooting steps to arrive at the conclusion that I wasnt getting +2v per leg off the output side of the RR, the stator was confirmwd generating proper AC. I dont have the necessary suzuki test set the service manual references, but I could read some pin combinations with my $200 DMM.
Bad RR?
Ordering parts mid late march/april 2020 was a nightmare, everything came slow. Replaced brake fluid, adjusted chain tension, topped off coolant, replaced hi beam headlight, new Ecstar oil/filter.

Eventually slapped on a new Chinese RR for $30 and tested voltage, ~14v
Golden! I feel dumb, at least I got the annual checks out of the way... typically I buy OEM or equivalent quality and was intending to buy OEM once confirmed.

100 miles later I went to ride an hour away and noticed a stutter/lag on bike start. I decided quickly to check voltage at idle and was only getting 12.4v across terminals.

I abandoned intentions to ride that day and threw the battery tender on. 3 days later I started it again and checked voltage at idle and saw 12.4v, and slightly lower at 5k rpm.

Before I take the airbox off again and go through all that work, anyone have suggestions? Is it the cheap RR? Is it possible Rick's RR wasnt bad and its something else? The only thing left is the 12v leg into the bike off the harness from the RR goes into a bundle of wires and disappears along the front brake side of the bike, towards the battery but splits under the tank. Some sort of short? It doesn't seem like there is any fuse between the RR and Battery.

Thanks for reading...
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So to summarize - I've got a new Rick's stator and a new cheap chinese RR, which initally output 14v across the battery but at some time shortly after install stopped working properly.

1 - Check accessories which use excessive amounts of electricity
does lo beam HID ballast count? installed since 2008, lo beam working as expected.
2 - Check the battery for current leaks
within spec, 1mv - Battery current (leak): Under 3 mA
3 - Measure the regulated voltage between the battery terminals
12.5v - Regulated voltage (Charging output): 14.0 – 15.5 V at 5 000 r/min
4 - Measure the resistance of the generator coil
within spec - Generator coil resistance: 0.2 – 1.0 Ω (Yellow – Yellow) ∞ Ω (Yellow – Ground)
note - none of the plastic connectors are melted, yellowed, or show evidence of issues.
5 - measure generator no-load performance
within spec, 71v - Generator no-load performance: 65 V and more at 5 000 r/min (When engine is cold)
6 - Inspect the regulator/rectifier
a very likely malfunction point, I got this far last time and replaced it with a cheap chinese RR and it seemed to work for a while and then failed. I plugged in the old Ricks brand RR again and it still didn't charge. There's a good chance that the Rick's RR went bad, and the cheap chinese RR was just that, cheap. There's plenty of advice around here to straight avoid these devices (Stator and/or RR).

step 7 is to inspect wiring. Since the Wiring seems OK and I know it was "working" earlier, I decided to get another Rick's MOSFET RR and see how far that gets me.

Stay tuned, for the sake of the thread I'll update with additional results.
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I got the RR in the mail this weekend and tested it, 14.4v across the battery. I began replacing the RR and tested voltage repeatedly as I reassembled.

When I removed the chinese RR I found this, which wasnt immediately obvious while installed, but obviously part of the problem, I verified the stator was good, but this is "AC in" off the stator. Only that fancy Suzuki diagnostic tool would have verified this for me.

So there is root cause. I'll fix it up and keep it as an emergency spare I guess.

I also ordered and installed this volt meter:

I do not plan to be without volt information any longer. Unfortunately it's a clock and temp gauge also. Tells military time only and temp in celcius.
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I too had a problem with Rick's replacement RR and was told by my local shop that GSXRs specifically do not like them. put a Suzuki unit in and no problem since.
I do have regrets about not buying another OEM one, but we'll see how things go.
Two thoughts,
First - is your R/R still in the stock location? Have you considered relocating it? I just recently went through the whole “no charging” series which had me replace the R/R first, then the stator a couple weeks later. I know you found the culprit was the wire plug and not the new R/R going bad yet but it seems like with our bikes it is doomed to be a reoccurring issue in the stock location. I found it was surprisingly easy to relocate the R/R and it also freed up the mounting space on the stock bracket for me to get my Stebel Nautilus air horn tucked in there and off my cluster area.
Second - your post actually inspired me to get one of those voltage displays, when my bike died again after I replaced the R/R I am pretty sure that was the closest my wife came to divorcing me because she was so pissed we had to double up on her cbr300r almost an hour away from home. Saw your post and I loved the idea, I wired it up directly to the battery with a rocker switch so it doesn’t have to be on all the time but I can turn it on while the ignition is off.
It sounds like you kept at least some of your sanity while ordering parts during COVID, glad you got the bike fixed.
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Thanks for commenting - I've seen people relocate the RR with a custom bracket to "face out" looking at the side, instead of facing front. It is something I am also considering next time, this go around is more of an experiment.
To be clear, the cheap chinese RR had the bad plug that I documented, I got a 2nd Ricks RR and things are stable. The el cheap-o goes into the bin of shame, I saved all the plugs from the known bad RR and would just solder them on if I absolutely needed a temporary RR down the road.

Also worth mentioning, I've read plenty here (and on other mfg cycle forums) that people ditch the plugs and solder all the connections directly. I have seen other threads here with melted plugs, and I would consider that in the future also, however that will make it harder to work on in the future.

As far as the voltage display, it was a good idea in my book, but it was also a cheap Chinese one and the instructions were poor. I found was it had 3 leads, I assumed black ground, red 12v source to read (battery), and blue as a signal/accessories. I ran it down through the left side with the throttle cables, along the left frame following my HID 12v run (and extended it, you'd want 4' to be safe). I didn't want to have to hide a switch somewhere and forget to turn it off and find a dead battery... The wiring actually turned out to be a bit different, black is ground, red is 12v battery (for keeping the clock current), and blue for "measured" voltage on the display. Initially I was getting varying voltage readings depending on what my blue wire was connected to.

Eventually I put the blue wire (which is the voltage it measures/displays) up into the fuse box right behind the battery and plugged it in with one side of the low lamp fuse (this is like 22 ga wire), and the bike apparently outputs unregulated voltage to the headlights so I am seeing not just flat 12v, but 14.7v most of the time, and less when the Hi beam is on, signals, etc. It turns on and off with the bike. However, as a result it "reboots" from accessories to start, but that's no big deal in my book. I have found the clock to be somewhat convenient, it's easier than reaching all the way into the cluster to switch around.

Overall I am pleased, next is to one-up the zip tie implementation. I am a bit worried about how waterproof it is and how it will endure, I fully expect to lose lines within each digit... Time will tell.
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