The Rundown-by Craig

[Astiryu1]

I bought the bike (2001 GZ250) used from a Harley Dealer. It was a trade in. It had just over 9,000 miles on it and had no real wear and tear to speak of save for a missing mirror. I got her home and started riding immediately:) As I got more and more confident in the tests I went further until I felt confident enough to go to school. A 30 mile ride one way and it dies halfway there for the first time. I get to school and call my parents to pick it up for me. Not the best part of Ft. Myers:( I get home charge the battery and it happens a few more times. So I buy a maintainer and a new (cheap) battery and it still does it. Looked up the problems and it sounds like it is the stator. I change it and buy a new (expensive) battery with my friend (also riding buddy) that works on bikes. Seems fine for a week then I go out to a friends house that is about the same distance to school and it dies on the way back at night in the middle of nowhere. Make call friend picks the bike and I up and that is the present situation. After changing the stator the bike actually has enough juice to start again on it's own but won't stay on. I think it is the electric rectifier/regulator. Other than that she rides better than my old bike and I don't have oily pant legs;)

[Rookie Rider]

Welcome aboard, is the petcock filter clean and not clogged ?

[Astiryu1]

i can check that but it really seems to be an electrical issue. Thanks for the advice:)

[jonathan180iq]

So you've done the usual stuff, like testing voltage across the terminals both at rest, at idle and running to make sure the stator is doing it's job?

You should be able to test current into and out of the rectifier.
I looked at the wiring diagram a while ago and had a pretty good handle on what symptoms would be caused by one going bad, but to be honest, it's been so long that I'm not fresh on it.

AlanTF is the resident electrical expert and he may chime in here soon.

Do a search for "rectifier" or "regulator" and search by Alan's name. There was someone with a similar issue (maybe 1 year ago, more or less) and Alan and I got into a conversation brainstorming how the thing worked. If you can find that thread, I'm pretty sure we can at least eliminate some variables.

EDIT: After reading that old thread and checking Alan's diagram, all you need to do is test voltage across the terminals with the bike revved up to see if the rectifier is doing it's job. It looks like it either lets juice flow through it or it doesn't. If you are geting 12.7+ volts acorss the terminals, then the rectifier is good. It sounds like beating a dead horse on this forum, but new batteries need to be charged before they are installed on these bikes and a new battery doesn't always mean a good battery.

[jonathan180iq]

Well, that was easier than I thought:

viewtopic.php?f=10&t=5954&p=65119&hilit=rectifier#p65119 (http://gz250bike.com/forum/viewtopic.php?f=10&t=5954&p=65119&hilit=rectifier#p65119)

:)

[mrlmd1]

How long ago did you get that bike from the dealer? Did you ever think of calling him up and discussing the problem with him and see if he will help you?
It's unlikely the stator or the rectifier went bad. Unless you start to test and diagnose the problem you will be replacing parts shotgun style until accidentally you may solve the problem.
Did you charge either of the new batteries before you started to use them? Both batteries you got are probably an AGM type and regardless what the dealer said, YOU must put it on a charger and fully charge it up before first use or after a few starts of the bike, it may fail, it will never hold a full charge. The battery is much more likely to be your problem than the stator or rectifier is. And to see if that stuff is working, all you have to do is measure the battery voltage at the battery terminals with a voltmeter, available for a few dollars, instead of whatever you spent so far and are intending to waste in the near future. If you get a reading of 13.5-14.5 V with the engine revved up to at least 2500-3500 rpm, your charging system is working properly and that is not the problem.
So, measure your battery voltage at rest before you start the bike - 12.6-12.8V is a fully charged battery. And then measure it with the bike revved up.
There is no significant current output from the charging system at idle, so don't waste your time trying to charge a battery that way - the best way is to ride the bike for a half hour at least.
Let us know what the battery voltage is at rest and revved up, then we can go from there. Don't buy any more new parts until that is done.
There are many other reasons why your bike could crap out, but let's start with the battery.

[alantf]

How long ago did you get that bike from the dealer? Did you ever think of calling him up and discussing the problem with him and see if he will help you?
It's unlikely the stator or the rectifier went bad. Unless you start to test and diagnose the problem you will be replacing parts shotgun style until accidentally you may solve the problem.
Did you charge either of the new batteries before you started to use them? Both batteries you got are probably an AGM type and regardless what the dealer said, YOU must put it on a charger and fully charge it up before first use or after a few starts of the bike, it may fail, it will never hold a full charge. The battery is much more likely to be your problem than the stator or rectifier is. And to see if that stuff is working, all you have to do is measure the battery voltage at the battery terminals with a voltmeter, available for a few dollars, instead of whatever you spent so far and are intending to waste in the near future. If you get a reading of 13.5-14.5 V with the engine revved up to at least 2500-3500 rpm, your charging system is working properly and that is not the problem.
So, measure your battery voltage at rest before you start the bike - 12.6-12.8V is a fully charged battery. And then measure it with the bike revved up.
There is no significant current output from the charging system at idle, so don't waste your time trying to charge a battery that way - the best way is to ride the bike for a half hour at least.
Let us know what the battery voltage is at rest and revved up, then we can go from there. Don't buy any more new parts until that is done.
There are many other reasons why your bike could crap out, but let's start with the battery.

:plus1:

Step by step is the ONLY way to go. Start with the easiest/most likely (i.e. battery) and let us know the test results at EACH step, so we can work out the next step. We're here to help you, but you've gotta help us by doing the tests that we ask you. :)

[Astiryu1]

Sorry I haven't been on for awhile I have been riding:) The problem is I got it used from a Harley Dealer where it was a trade in. They "say" that they never even checked it out since it was rode in and worked fine for the week they had it until I bought it "as is". I totally started with the easiest parts first I have put in 3 batteries the final one being a Yuasa instead of an Advanced Auto cheapo then a (rebuilt) stator. Most of the issues are fixed except for the new round. After going about 50 miles it loses it's charge and won't start with the key. I can pop the clutch but only so many times. When I engage the clutch it shuts off (initiating another momentum powered clutch pop;) ) I have done this twice so far but I charge it every time it goes bad like that. I do have a battery maintainer/charger for motorcycles and a volt meter that has seen it use lately.

[Astiryu1]

I will work on the tests tomorrow at my friend's place most likely. I unfortunately have no tachometer though so the rpms will be guesswork. I have been wanting to get both a tach and a voltmeter rigged up by the speedometer since I got the bike. Maybe now is the time;)

[PimpS]

Hello!

In my case it was rectifier, after it was changed with a new one, GZ worked normal. In my case was that, when bike wnet dead, the battery was emptied too. Astiryu, if i understand correctly, you have already changed the battery 3 times, isn't there any insurance from a shop you bought the bike? Any way; i hope you'll get the GZ started and riding the hell out of it... Good luck!

PimpS

[alantf]

I remember, with pimp's bike, that I said that, usually, a rectifier either worked or it didn't. Turned out that it must have been an intermittent fault, because he changed it and the problem went away. Seems like there's something weird about the gz rectifier, if it's doing the same thing on another bike. :??:

[PimpS]

Alan: I must agree on that about gz's rectifiers. I remember that to a mechanic guy it wasn't strange, cause he immediatly said it was a rectifier (that's why I was suspicious), but later when all was ordered, mounted and fixed I spoke to my friend, who also was saying simlar things like you, he said whether the rectifier is dead or not, but in my case it was like he worked and then stopped working... Considering the fact that my bike made 5000km after that with no problem, (same battery, new rectifier), those rectifiers are cranky :) Again, thanks for all the input to check everything to find real cause, before you spend your money. Astiryu, keep us informed what solved the problem, it makes this place so much valuable to all of us. Ride safe!
ps. Due to my dentological problems i can't ride for another week... Damn!

[raul10141964]

some time rectifiers and CDI work cold an stop on hot

[PimpS]

raul: exactly.

[mrlmd1]

It doesn't matter how many times you changed the battery - if you don't charge it up fully before you use it, it will crap out and you can keep doing that ad infinitum. You can keep charging it all you want - you have already ruined the battery by not charging it up before you started the bike with it he very first time. Understand what I said?
I also went through 3 batteries before discovering that the battery itself was not the problem. These batteries MUST be charged up by the user first to a full charge, and that comes direct from a conversation with Yuasa and with every other AGM battery manufacturer if you read the enclosed directions in the box. So the problem may be very simple to solve, and it is YOU, not the battery.
And all the anecdotal remarks on here about how others solved their problem by doing this or that is a total waste of time. Unless you do things in a stepwise fashion like I said, you are just spinning your wheels and if you get lucky by replacing some part, you just got lucky.
Do yourself a favor and go about this in a stepwise fashion and give us the results after each time we ask you something. And at least alantf agrees with this approach. If you want your mechanic/biker friend to solve your problem, then let him do it. The worst thing is to ask for advice, get some good advice, then do what you want anyway and come back and ask for the same advice again.
Sorry for the rant but that's the way it is.

[Astiryu1]

I charged the battery(ies) fully; multiple times (once before riding at all) and many more times after the eventual and almost predictable failure. I have went at this step by step with my friend that knows much more about bikes than I do. First step: was finding out that the batteries were failing changed battery(ies), kept having problems. Second Step: Pin pointed the stator it was throwing bad readings and has been changed, there is improvement but not to full working order obviously. We have went through the wiring harness (multiple times). The "problem" is not the battery but the battery keeps going dead which is an issue. There is something/multiple things wrong in the system that makes the batteries fail. Basically I think this problem was happening and that is why it was traded. The Harley dealer sold it "as is" so I am not getting any help from them... I prefer to keep my money in my bank account lol. That said I will post the results of the tests as soon as I can. I am not ignoring anyone on the contrary I am following what has been posted as a way to fix the problem(s) but there is the fact that the bike isn't sitting in a garage being tested all day it is my only form of transportation and therefore problems are attacked when they are presented.

[Astiryu1]

I am now in what I consider the 3rd Step. There is still an issue that drains the battery (which I consider a symptom). Considering that the bike has improved since I changed the stator it is not that but was an issue before. My Question: If there is a drain/short and/or bad rectifier would riding back and forth to school and work (between 20 and 40 miles one way for each) be ill advised until the issue has been fully resolved?

[Water Warrior 2]

Disconect the battery and leave the bike parked until you can get the time to fix it properly. If there is a bare wire or short somewhere you may do more damage or even start a fire in the wiring. Nobody wants a flaming bike and a tank with gas in it. I would want to be safe rather than sorry.

[alantf]

You said that you'd checked the wiring several times. If the battery had been knackered ,also, several times, it sounds more like a short circuit or overcharging. If it was just a leak to earth, you'd probably just discharge the battery, then be able to charge it back up again. Same if the rectifiers went bad, and didn't let juice through to the battery.

Just a thought, with no test results to back it up, but there's a voltage regulator in the same unit as the rectifier. Have you tested across the battery at around 4000 revs (To make sure it's charging) and made sure that it's not kicking out too high a voltage, because that's what usually fry's a battery, not draining it.

[mrlmd1]

To see if you have a short somewhere, you can disconnect the negative battery cable, or ground, from the battery, and then to that negative battery terminal connect one of the leads of the voltmeter, (set it to amps), and the other lead of the voltmeter connect to the negative (ground) cable. You should get no current reading with the bike turned off unless you have an open short somewhere. If you do measure any current, you will have to trace the entire wiring harness looking for a short - an abraded wire rubbing on the frame somewhere or inside the headlight bucket. You could have an abraded wire not directly contacting the frame, but have dirt and moisture around it causing a slow current drain and not enough to blow the fuses.

Did you ever get the bike running and measure the battery voltage at midrange rpms (2500-3500 at least) like we have asked and see what voltage the charging system is putting out? If you don't do that, you cannot analyze anything.

[Astiryu1]

My problem with referencing the rpm's is there is no Tach:(

The voltage rectifier is throwing a reading of 11.75 when the key is off and I have the trickle charger hooked up. Should there be a reading from it while the bike and key is off?

After talking to two friends "My Riding Buddy and another that knows a bit about car parts" the issue of the kickstand switch may be to blame. Is there any way to diagnose the kickstand switch as the offender. Sometimes it gets "sticky" from dirt and oil and doesn't open up to allow the bike to start. All I do is depress it a couple times by hand and I am good to go. I understand that I may have to replace that soon anyway according to what I have been told at the local Bike shop where I get misc. parts.

I will test for a short tomorrow when it isn't raining lol. Thanks for the run through on how to do it.

[Water Warrior 2]

The side stand switch can be cleaned up nicely with WD-40. Put a pan under the bike and hose down the switch with WD while exercising it a bit. Did the exact same thing to my Vstrom a couple times over the years. The switch is easier to get at from the right side of the bike while it is leaned over on the stand. Then give the stand pivot bolt a shoot of chain lube to keep it smooth and easy to operate.

[Astiryu1]

My friend and I were wondering if there is a possible bypass for the switch.

[jonathan180iq]

To bypass the sidestand switch? Sure.
It's just a built in kill-switch. You can bypass it and wire it like the stand is always up. People on here have done it but it hasn't been talked about in a while.

That being said, it's a safety feature. It's not hard to repair and doesn't cause any problems as long as it's working... It's either on or off. I don't think it's connected to your other issues.

[mrlmd1]

Just FYI - it's not a good idea to eliminate or bypass the sidestand safety switch - it's there for a reason. If you ride off forgetting the sidestand is down and you make a left turn, you will go down as the stand hits the pavement and picks up the rear wheel off the road.
It's hard to believe there could be so many problems with this bike and you are having to replace so many parts. Most problems are due to failure of only one part and you just haven't found out yet what the problem is. At least when you replace everything, maybe you'll get to solve the problem and have a fine running bike.

[mrlmd1]

I just re-read you posts and you said before that when you let out the clutch the bike dies. If you had it in gear and the sidestand was down, that would be a normal occurrence, as a safety feature. Does it die if the bike is in neutral? Does it die if the sidestand is up?

Another reason batteries die overnight is that the owner, when shutting off the bike, mistakenly puts the key into the far left PARK position and leaves the rear lights on and may walk away from the bike and not notice that, leading to a dead battery in the morning. If you check the ignition key switch, you will see where the OFF, or LOCK, position is, in the middle of ON and PARK, and this is where it is supposed to be when you turn off the bike. Check on that.

[Astiryu1]

At least when you replace everything, maybe you'll get to solve the problem and have a fine running bike.

That is what keeps me going actually...

[Astiryu1]

Oh yeah I made that mistake once...not after that though. What is the deal with that anyway? It dies when the sidestand is up. Usually when the bike comes off of a hard run at 70mph for about ten miles. That is the last stretch of road to my house between the cities.

[Water Warrior 2]

It dies when the sidestand is up. Usually when the bike comes off of a hard run at 70mph for about ten mile
Maybe the bike is trying to tell you it doesn't like 70 mph for 10 miles. Try 60 mph the next couple times.

[Astiryu1]

It does it anyway lol. That is why I think it is the rectifier. It does it randomly it seems too. Icould go the same amount of time at 30-50 miles an hour and it just starts cutting off when downshifting and I get towards my house.

[Water Warrior 2]

So much for my idea. Carry on.

[Astiryu1]

It was a very valid thought. Any input helps me:)

[alantf]

it starts cutting off when I get towards my house.

Perhaps it just doesn't want to go home. :whistle: :crackup

[jonathan180iq]

The rectifiers are $147 from Ronayers. Search the for sale threads here and see if you can't get one off a parts bike and eliminate the variable.

[PimpS]

Astiryu!
In my case, when rectifier was bad, before bike went dead totally (2km before) the bike was full throttled and it stalled(like something disrupted his machine) and then went on for 2 km and died... Does that happan with your bike too?

[Astiryu1]

More or less
I agree with it not wanting to go home too:)

[Astiryu1]

Put the Bike in the shop to get it fully worked over. A week later the diagnosis was as suspected a bad Voltage Regulator. I have had it back for about two weeks now without any issues at all. Seems as though that gremlin is gone. The rest is simple stuff like a speedo bulb and that is something I can handle for sure. The numbers thrown on the bad regulator were around 6.50 and the good one is up to 13.50.