FZRSupport: the FZROnline Archive

Hi all,
I'm am extremely happy to say that after a 6 year haitus, I'm back on a motorcycle. I bought an FZR with 37K miles, great feeling engine and transmission. Super cheap.

The guy who had it said that it developed a stutter at high rpms when he was riding it daily. I noticed (I work at a motorcycle battery company) that the battery was at the low 11 volts, and when I started it up it raised up to mid 11 volts. Then the higher I revved, the lower the voltage dropped -- down to the ten volt range. I tried another used regulator and it did the same thing with a slightly higher idle voltage.

Then I put a new regulator on it (for an r6 - same connector but 6 pins, the extra which I grounded but also tried ungrounded) and it went past 17 volts!!! I tried redundant groundings all over.
The (lead acid) battery, which came with the bike came to rest at 12.8 volts after that and it still cranks fine. The stator tested out at around .35 ohms each, and weren't grounded out. 30 volts AC each at idle and rising consistently upon revving. The key off discharge is a big fat zero.

Did I get three bad voltage regulators (one being new) and do I really need to get a third, or do I need to start pulling the tank and checking wire harnesses etc, and any tips on what to look for?
It's killing me not being able to ride, because everything else is checking out fine on this bike.
Thanks for any tips!

Your diagnostics so far certainly indicate the VRR as the problem. It's odd but not impossible that you got two 'failed low' used regulators; 'failed high' is more common, but failed low certainly happens. It's odd but not impossible that you got a bad new regulator - was this from a reputable source, or an El Cheapo Chinese copy?

How have you grounded the new 6-pin? The top-center pin serves no particular function with the FZRs; the top right (facing the regulator pins) is the ground pin. It should be connected directly to the engine cases with a dedicated 12ga wire. It is not impossible that, if the grounding method was incorrect, that you killed the new regulator almost immediately.

Check for continuity and resistance from the red VRR connector terminal to the battery, and again with your ground wire.

I used the stock wiring harness plug directly.

The black wire is grounded to the negative terminal and frame.

How do you say cheapie in Chinese?

I have some old Ducati one that I might wire up...the shipping wait is agonizing but I don't want to risk running it as total loss if there are any unforseen issues with that.

Update:
The second new regulator did the same thing as my original. I think it's a wiring/other issue. Could it be my stator?

So this second new regulator puts out 13 volts at idle and drops into the 12's on revving.

Problems with your stator won't kill your regulator, and your stator resistances and AC voltages sure sound like it's working properly.

Can you post a pic of your VRR and connector?

Just left for work agai, I can upload pics in 4-5 hours...

it's this one
http://www.ebay.com/itm/261312407704?ss ... 1439.l2649

5 pins like stock.

Also I will be testing with a different battery today; i am not totally familiar with all the failure modes of this lead acid battery but maybe it's causing the problem. Arg!

It's a 1996. there is an extra ground wire coming from the stator side of the plug that is supposed to attach like a washer to a bolt....i attached this direcly to the voltage regulator bolt that goes through the body.

I would suggest measuring the resistance from the ground pin of the connector to the battery -ve terminal. When you're talking 20-25A, it doesn't take much in the way of resistance for P = I^2 x R to reach melty numbers. Also, a bad ground will kill the VRR fast. You've just killed two VRRs in short order, and running your bike at 17v (>>14.5vdc!) will kill everything else in your harness. Park it until this is sorted out!

Ok well this last one peaked at 13.05 volts at idle and dropped as I revved. On the last one I didn't see 17 volts for more than a few seconds before I shut it down...but this current regulator already got quite warm in less than a minute. Seems too fast...

Yeah I think something is shorting, but based on my initial readings, nothing extra is shorting, arg. I am though starting to think I may have a short even though I have no key off draw. ???

I'm at work but i believe both ground connectos (main stator connector and extra bolt ground connector) were at .02 ohms to the -ve terminal so it has a good connection there...
You can tell though I haven't diagnosed electrical, i guess now's the time to learn.

Thanks for the help tho Don... If i fix it I can throw a few bucks at you paypal or something to you. I just know i won't be able to sleep tonight if I can't fix this.

I have seen a bit of corrosion = resistance = voltage drop = melt wires before, let me tell you

I am now using a brand new battery to eliminate variables (luckily these things are plentiful for me )
Here's my question now:

ok, second new regulator:
according to this flowchart
https://www.electrosport.com/media/pdf/ ... iagram.pdf
the voltage between the negative battery terminal and the negative pin at the regulator at idle shouldn't be more than .2 volts. I'm at .19 - .2V.
So I'm thinking corrosion...

now when I add a direct chassis ground to VRR ground AND a Positive terminal to positive VRR pin wire, presto I get idle at 14.2 volts and ~5000 around 14.1 to 14.0 volts.
**my question** is...is this 100% standard behavior, or should it absolutely run at a lower voltage and charge at a higher voltage with higher rpms?

In other words, do I really need to get down to it and fabricate a new damn point to point wiring harness or is this completely acceptable? And is it safe, for the sake of my electronics speaking, to ride now? (With an LED voltage meter permanently hooked up of course).

Thanks!!

There's a reason I include a point-to-point ground wire with my adaptors - the wiring in your harness is 15-20yo, undersized when new, with corrosion, cross-fretting, animal gnaw marks, blah blah blah. 14vdc is a nice number; it may be drawing down slightly as the revs climb because the battery is still charging while the ignition load is increasing directly with engine speed. Inspect your stator connectors for fouling and corrosion; 30VAC is pretty much the lower limit, and any AC or DC losses will make the entire charging system marginal.

Am I ok to ride it for the time being with a voltage meter? I know you will wash your hands of an assessment of any risk inherent in your advise but I'm just looking for context...reliability is questionable at this point until I wire up a new harness myself? 18 year old harness, I agree...But I'm not looking forward to making that...

It'll be done but I'm crazy busy so I'm hoping to delay a month or so. I will keep putting the effort into this bike but I'd like to use it as a semi-daily while working on it.

If you're seeing ~14v, that's a good safe number. You are seeing some odd behavior, so it's definitely worth while to do some connector checking as well as the soldering at the stator. Don't worry too much about running the white or red wires unless there's obvious damage; it's the ground that will kill your electrical system.

I took it for a 45 minute test and it was basically pegged at 14.2 the whole way. Looks good to me all though I will be going through it much more. Don thanks a lot for your help, if you pm me a paypal I can send a small thank you.