At the mechanics shop

[PimpS]

I am one of those guys, who doesn't feel good to play with the screws on machines. When it is about to make a table by a simple instructions, or to mend some brakes on a regular bike - no problem. That's why i give my regular and non regular service of the bike to a pro, to do his job, and i pay for it.

So, to make my story shorter: i got spokes from 5_th bike, got a new sprockets and DID chain... My regular mechanic was in deep bussines and he couldn't take time for me, that's why I went to this other guy.
Everything cool, but next time i'll write down on a piece of paper what to do, what is advised to do, cause the guy lost my spoke, even forgot to change it. He did set my valves and the bike runs a bit different, also i feel he is running easier. New chain, new sprockets... it's cool...

Today i hope he'll do the job right.

I got the feeling that some mechanics are not taking us seriously, considering the bike, like GZ, we ride... :?

I don't know, it's time to develop mechanical skills, buy some tools and start doing as much as I can/dare ;)

[jonathan180iq]

For most of your everyday maintenance needs, we have tons of how-to's here on the site, with pictures and explanations from others about their experiences trying out some pretty advanced maintenance items on their own for the first time. Don't be scared to dive into something. Doing something knew and taking a shot at something that you think you otherwise couldn't do is how even the most seasoned mechanic became a pro. It's also how we learn to do things as children that we take for granted as adults. Learning is always an awesome experience, even if it involves a couple of bloody knuckles, a curse word or two and maybe 16 hours to complete a 3 hour job. ;)

[PimpS]

LOL, yes Jonathan, i'm getting there. Otherwise, i got my gz back and went for a ride, at 36 degrees celsius in full equipment... Phew it was hot. I'm not sure if the setting of valves made a bike going better (that is stronger and faster), I couldn't get higher than 105 km/h, usually i got it to 115 km/h. Machine is in my perspection getting more thumps, if before that went thump...thump...thump..., now it goes thumpthumpthump... i haven't mess with idle speed...
Don't know. Otherwise is going well, the good achievment today was, that i felt really secure on the bike and even scratched the floor with peg going into curve, and it didn't scare me ;)

Friend told me, man you're getting better and better and you are starting to feel the need for more and bigger...

PimpSerS is a OK for me! ;)

[jonathan180iq]

it really depends on how far out of whack your valves were as to whether or not you should read or experience different sounds coming from the engine. If they were close, then you shouldn't notice anything different at all. If they were really too loose or too tight, then you should have noticed some issues getting the bike started, that have now vanished. Are you sure it's not just in your head?

Is it an actual thumping that you hear, out of the exhaust, or are you hearing knocking in the engine? It could be that those guys set it wrong. It has happened before in the wide world of bikes.

[PimpS]

ay be you are right about my perception, but to make it sure, i'll drive to my mechanic and he should know better... Thanks Jonathan, you and many others here are voice of wisdom!

[PimpS]

Got my santa barbara today: after work i decided to visit my friend at the river, about 1 hour beautiful ride. Came home, pack things up and off i go. After 15 km my GZ went dead. Before that, i was overtaking 2 cars and in between gz gave me a sudden push (like i would shift down) and back to normal, full throttle. After 2 km in the crossroad, it just went dead, i mean totally dead, no light in neutral, nada...
After a while the neutral light start to blink when the key was turned on.
I called the mechanic from yesterday and he told me what to try (check battery, fuse...) came to me in half an hour, we started the bike with the plug and went to his shop. In the shop he discovered that electric regulator or something went down and we ordered new one... 190 €... Geeez, i didn't complicate and i ordered it, i get it in 5-10 days... I'm sad, but happy that it went dead now, not in 3 weeks time when i'm off to the sea side (276 km in one way)... I hope that from now on everything will be just about maintenance :)

[alantf]

we started the bike with the plug

Sorry, don't understand. Can you explain what you mean? Perhaps you're using the wrong word. :)

[PimpS]

Battery connected to the car... My battery was dead, and after we started with the car i had my lights turned off, actually i was driving with park lights, but later i turned them off too. When in sorrow, my english gets worse ;)

Rectifier is the thingy that went down, checking the internet i see that these things are much cheaper in states... For 50%, i'm getting rectifier from suzuki dealer, as mechanic stated... Ehhh, my crash bar is put on hold for a while...

[jonathan180iq]

So after you started the bike using jumper cables, the bike kept running? Were you able to charge the battery while it was off the bike?
Did it die just while you were cruising down the road, or did it refuse to start after you had parked it and left it to sit? (From your story, it sounds like you were riding along, come to stop or something, and the bike quit. But if it was able to restart and run after being boosted with cables, then I would suspect something other than the rectifier. If it kept running, even with a shit battery, you know the stator and rectifier are fine, right? (Someone correct me if I'm wrong, cause I hate electrics.) Certainly it didn't keep running even after being jumped....

I'm also surprised that you can control when your headlights are on or off. We are forced to have them turned on in the states, all the time. ;)
Or do you mean that they wouldn't come on?

[PimpS]

Well, as i said before went dead the machine went two times strange way in a 1 km distance (having a full throttle and for a moment it made a twitch, like i would let down the throttle and machine would make a brake, but really in a moment, it was strong as it moved me towards the handle bar), later (after 1 km) i came to a crossroad, i was braking but during that the bike went dead. I pulled over, i got it to neutral, tried to make it start - nothing, because of the sun i couldn't really see if the light on neutral is on. I put the bike in the shade, tried to make it start, but the light on neutral hasn't been lit and the bike didn't say nothing. I called mechanic, which told me to check battery, fuses... After that (10 minutes) i tried again, the neutral light was blinking and around fuses there was a squikky sound when trying to start the bike (battery down i guess). Changed the fuses, even though they were both good - i prosume i have a spare fuse beside the fuse. When mechanic came, we made all the inspection from above again and he said we will try to make it start with cables. The bike came alive insantly and he said that whether the battery is crap or regulator-rectifier went down, since the lights i had them on during the ride have used all the juice in the battery, since rectifier wasn't making his job to provide juice to battery. I was riding without lights, to spare the juice. There was no cops, thanks god, or bad traffic.
At the shop he tested the battery with a tester while the bike was running, and the battery was fine. I turned of the bike and i was able to start it with no problem. He said that it must be rectifier. He told me to go home, take out the battery and bring it to him to fill it up and wait till the rectifier comes...

I hate bad electrics too, today some folks i was talking to them, told me that on smaller engines (till 500ccm), electrics can be PITA, so I should get use to it... F...!

Thank you for responses, past and future!

ps: is it possible that somewhere the ground electrics has a bad contact or something?

[alantf]

At the shop he tested the battery with a tester while the bike was running, and the battery was fine. I turned of the bike and i was able to start it with no problem. He said that it must be rectifier.

Correct me if I'm wrong,but............The bike wouldn't start, but started with the car battery. This points to bike electric problem. At workshop, mechanic tested battery, & it was now fine. That means that the charging circuit charged the battery on the way home. So how could the rectifier be faulty? Also, you say he tested the battery with the engine running. That means that the battery was on the bike. From your description, it seems more likely that it's a faulty battery. You need to take the battery off the bike, fully charge it, let it sit (possibly overnight) then take it to someone who can do a proper volt drop test on it.

Even though he said the battery was fine, I bet he just used a voltmeter. This would just show that the battery had taken a charge while you were riding (and hence rectifier problem not possible) but couldn't show that the battery could hold that charge for any length of time.

Jonathan.... Over here, the bikes are all fitted with lights that are always on, but that law only came in, in Europe, in the last few years. Dunno what year exactly, but all the 9 or 10 year old bikes that I see, still have a light switch.

[PimpS]

OK Alan, thank you again for your cooperation, i really appreciate it.

Tell me something: as I understood mechanic: the bike went dead in first place because the lights emptied the battery during the ride, cause rectifier wasn't functioning properly. Is this reasonable?

I was able to start the bike on its own, when going home from mechanic. Obviously the battery got charged during the 15 km ride to mechanic. Is it possible that rectifier isn't working properly (sometimes is working and sometimes is not)?

Thanks!

[alantf]

OK Alan, thank you again for your cooperation, i really appreciate it.

Tell me something: as I understood mechanic: the bike went dead in first place because the lights emptied the battery during the ride, cause rectifier wasn't functioning properly. Is this reasonable?

I was able to start the bike on its own, when going home from mechanic. Obviously the battery got charged during the 15 km ride to mechanic. Is it possible that rectifier isn't working properly (sometimes is working and sometimes is not)?

Thanks!

It is just possible that there may be an intermittent fault on the charging circuit, but highly unlikely. My first guess is that the battery is not holding its charge. This could be caused by a faulty battery, or an intermittent short circuit somewhere in the wiring harness. I still suggest that the first step is to charge the battery, let it sit, then get it PROPERLY drop tested. The next step is to try and visually check the wiring harness for earths (grounds, as the Americans call them). I still could be wrong, but I reckon the faulty rectifier is highly unlikely. (I've been an electrician all my working life) :)

[Water Warrior 2]

190 €... Geeez
Good grief thats a lot of money. Do some checking like Alantf has suggested. You may save yourself a bunch of money or confirm the need to spend that much.

[alantf]

I told you stuff's expensive in Europe, (relay) didn't I? :) I had to pay €133.16 ($167.12) for an injector for my Citroen. :cry:

[Water Warrior 2]

I told you stuff's expensive in Europe, (relay) didn't I? :) I had to pay €133.16 ($167.12) for an injector for my Citroen. :cry:
I remember the relay story. That is outright theft in my opinion. The injector should be a common off the shelf item to my way of thinking. It isn't like a Citroen is a strange little foreign car in Spain. Or is it that the injectors are so reliable that no one stocks them and they are hard to find.

[PimpS]

I checked the ebay and i could save 80 €, but having the experience of waiting shipment from US (said 5-13 working days) eventually ended with 20 days. I really have the need to experience ride to sea side in croatia, and extra 60 € means a wish come true.
My original mechanic whom i have called 1 hour ago, was assuring me, that it is the rectifier with not proper operating, without a doubt.
Mechanic who picked me up yesterday called me and said that battery is ok for sure.
Well, hope this story will have a short and quick ending.

Thank you guys!

And yeah, europe is expensive and looks like everywhere is bursting, i hope the bankers won't start another world war...

[Skunkhome]

And yeah, europe is expensive and looks like everywhere is bursting, i hope the bankers won't start another world war...
I am with you, isn't that what happened in Yugoslavia in the 1990's . The government nationalized (stole) everyone's bank accounts to pay off debt and forced everyone to hold checks until inflation made them worthless. The streets soon ran red with blood.

[alantf]

The injector should be a common off the shelf item to my way of thinking. It isn't like a Citroen is a strange little foreign car in Spain. Or is it that the injectors are so reliable that no one stocks them and they are hard to find.

This was off the shelf at the Citroen dealer's, but the checking & fitting was only €35 ($43.91) including taxes. Parts are expensive, labour cheap. Had an oil & filter change, last monday. Total price €41.22 ($51.69) including €1.22 for a couple of clips that they spotted missing from the bonnet stay (I'd forgotten to mention it to them) I trust them more than the little mechanics' shops. They have the parts without having to wait for them being imported, often do little jobs they spot, for free, & are a pleasant bunch to visit.

[alantf]

My original mechanic whom i have called 1 hour ago, was assuring me, that it is the rectifier with not proper operating, without a doubt.
Mechanic who picked me up yesterday called me and said that battery is ok for sure.


Did you ask him what test he did, to be certain that the battery is o.k.? If he used a voltmeter, and not a load tester, it's just him crossing his fingers and guessing!

I did this for a living, and I wish I could be as certain that it's the rectifier. All a rectifier does is change the A.C. output of the alternator to D.C. to feed the battery. I still maintain that as the battery recharged itself, there's NO way it could do it with a faulty rectifier. Still, I hope I'm proved wrong, and you haven't wasted your money. Even if you fit the new rectifier, and the bike runs, it doesn't prove that the original rectifier was faulty. It could be any number of other things (intermittent faults). I certainly don't have the faith you have in your mechanic's electrical knowledge. :??:

[jonathan180iq]

Tell me something: as I understood mechanic: the bike went dead in first place because the lights emptied the battery during the ride, cause rectifier wasn't functioning properly. Is this reasonable?



The idea that using the lights used up all of your electrical system power doesn't make any sense. Batteries on vehicles are generally only used to start the vehicle and to be a source of back up juice during periods of low output by the alternator/generator/stator. Once cranked, the stator is the thing that is making electricity flow through the bike, not the battery. (Although the battery is part of the circuit.) So suddenly having the bike die on you, while riding, sounds like something other than just the rectifier. As Alan mentioned, I would suspect the battery would be the faulty link, since you said all of the fuses were fine.

If your mechanic checked the battery while it was still attached to the bike and the bike was running, then the reading he would get across the terminals would be 12.5-13.7 volts. He would assume that the battery was fine, even though it very well might not be taking the charge. And a drained battery, or a battery with failing cells, can short out the whole system.

I had the exact same thing happen once while driving a Ford Focus down the road. It suddenly would just cut out while riding. Trying to force it through the episode, I gunned it, solving the problem for all of 3 seconds until the car shut off completely and I had to drift to the side of the road. Upon inspection under the hood, I could see that the battery was actually bulging along the sides. Something in the internals of the battery had failed and everything was shorting out. I removed that battery, had it properly disposed of, and installed a new one. That was 3 years ago and there hasn't been another issue since.

As mentioned, before you do anything else, you need to have the battery taken off the bike, charged fully, and then load tested.
If that ends up being the problem, it should be much cheaper than 190€.... At least I hope so. Who knows with those zany Euro prices ;)

[alantf]

[attachment=0:k37lu9ad]img036.jpg[/attachment:k37lu9ad]Pimp, will you print this circuit diagram, and show it to the mechanic? Ask him to explain how the battery could charge if the rectifiers were faulty - see if he can even identify the rectifiers - and if he comes up with an explanation, will you let me know what the explanation is? I'm dying to know. :)

[alantf]

it should be much cheaper than 190€.... At least I hope so. Who knows with those zany Euro prices

Around €50-60 in Spain. ($80-90)

[alantf]

I 100% agree with Jonathan. If he tested aross the battery with the bike running, and got a good voltage reading, then this proves conclusively that THE RECTIFIERS ARE FINE. Unfortunately, IT DOES NOT PROVE THAT THE BATTERY IS FINE. How many more times do we have to tell you REMOVE THE BATTERY FROM THE BIKE AND HAVE IT LOAD TESTED. This is (as Jonathan, also, pointed out) THE MOST LIKELY CAUSE. Phewwwwwww! :yes:

[PimpS]

Hmmm... I'm getting strange feelings now. SO, if the rectifier isn't the case nor battery, what else could it be?
Load tester? Does load tester measure amperes or watts? What should load tester show, how many of the units (amperes or Watts or something else...?)?

Skunkhome: war in Yugoslavija wasn't about banks, checks... Actually, war that was here was, sad but true, really a cookie to some other major countries, it was a classic war thing; let's sell and test our new weapons, let's make bussines better (major drug link from asian parts (afganistan...) went through yugoslavija to western world. Having war in this part, was a real favour to criminals, since situation waqs out of control...
I don't know about you guys, but the reasons which are told to be the right reasons for war, such as join the army to make peace, your country needs you, defend our politics, since is the only and right one, is just a crap. Wars are actuallly forced through greedy corporations, even individuals, who made huge profit and control out of it, human sacrifices are just the colateral damage. Naomi Klein and the book Shock Doctrine is a way to see these things differently. Take a 4 hour of your time and watch Zeitgeist the movie, and Zeitgeist Addendum... Whole new perspective of the social system, that we live in...

Ok, lets leave the politics, don't want to push any of your buttons, but stay alerted and open minded.

[jonathan180iq]

Hmmm... I'm getting strange feelings now. SO, if the rectifier isn't the case nor battery, what else could it be?


We believe the battery to be the problem, my friend.
That needs to be properly tested first, before you can make any other diagnosis.

[PimpS]

ok
Thanks guys!

[alantf]

Hmmm... I'm getting strange feelings now. SO, if the rectifier isn't the case nor battery, what else could it be?
Load tester? Does load tester measure amperes or watts? What should load tester show, how many of the units (amperes or Watts or something else...?)?



I'll try and explain simply. A load tester is a piece of equipment that has a voltmeter, and a built in, switchable load (usually a resistor) The battery is taken off the bike so that the battery, and only the battery, is tested. The operator connects the terminals to the battery, and reads the voltage. He then switches the resistive load on, for a given time, then checks the voltage again. That way, knowing the size (ampere hours) of the battery, he can tell if it's good or not.

One step at a time....have the battery checked first, then let us know. If your mechanic hasn't got a load tester (and I don't think he has) you may have to search around, maybe a big workshop that services cars, and sells batteries. But this is DEFINITELY the first step.

[mrlmd1]

All of this can be caused by something very simple - you may have had a loose battery connection which intermittently prevented any juice from coming/going from the battery and the causing the bike to die. It can either be the pos or neg connection, and it also could be at the engine ground.
Before you do anything else, simply check your battery terminal connections - clean them up 'till they shine and reconnect them tightly. And clean up the engine ground. This may just solve your problem. There is most likely nothing wrong with either your battery of your charging system with all the confusing testimony from glancing through this thread.

[alantf]

But still get the battery load tested. It's usually free, and it's one thing you can then cross off your list.

As for confusing testimony, we've been telling him all along that it's NOT the rectifier. The only confusing thing is why the mechanic did the wrong test, then told pimp that he needed an expensive repair!

I don't know if you've read the previous posts, but you'll see that I advised him to have the battery load tested first, then let us know. We've a hunch that it's a faulty battery, but no way of knowing, without a test. If the battery's faulty, then that was the problem. If it's ok, he can put it back on the bike, knowing that that's not the problem. Then we can lead him, step by step, through the next steps, such as making sure all the connections are tight, and getting his assurances at each step. That's the only logical way to go about fault finding for someone who's not up on electrics. The main thing we've been telling him over and over again is that the mechanic carried out a non valid test, and the faulty rectifier was the least likely of all the culprits. Given the nature of the original fault, he's got to be certain that the battery's good. I'd hate to have him THINK he's found the fault, then break down again, miles from home. I'm only advising the sequence of tests, in the order that I was taught to carry out in my job. I always carried a small load tester, so that I could first check the back up batteries on electronic panels, and it saved me hours of searching. :)

[PimpS]

Ok guys, since my battery is at mechanics, still receiving the juice from the charger. I explained to him that i will take the battery to test it for a load. He said that is no problem, still he is convinced that is the regulator, i forgot what he told me, but he was saying something like if it would be faulty energy, the bike wouldn't start... So, i am no expert, i'll take the battery to check and will let you know. If the battery will be the issue, i have no plan to pay for the regulator.

1 more thing guys: is there a way to check for rectifiers consistency, a way to check if rectifier is faulty or not?

I will also clean all the connections, although as seen yesterday, they are clean, not shiny but not green also...

Also, where is the engine ground connection?

thank you for your help and enthusiasm, you rock guys!

[alantf]

[attachment=0:qdnentp9]img080.jpg[/attachment:qdnentp9]The only way to test a rectifier is to check the forward resistance of each plate, but I don't know what the resistance should be, and I don't think you're up to it. A rectifier is only (each plate) a gadget for allowing current to flow one way, and not in the reverse direction, so that the forward/reverse flow of alternating current is converted into the forward only flow of direct current.

Here's a simplified drawing of a little bridge rectifier that I made (using blocking diodes) so that I could fit a 12v dc buzzer to our 12v ac door entry system. If you follow the path, each way, from the ac to the dc, you'll see that in each case, current must flow from left to right across the dc terminals in each case. The diodes simply let the current flow in the forward direction, but not the reverse. You can see from this that if any diode went faulty, then we wouldn't get true dc across the dc terminals. That's why I said that your rectifier can't possibly be faulty, or the mechanic wouldn't have got dc at the battery terminals. there's really no need to test - you're either getting dc or not.

By the way........sounds like the mechanic's trying to baffle you with bullshit.

[jonathan180iq]

To break that down, if you can test the voltage across the battery while the bike is running, then the rectifier is fine. DC juice wouldn't be flowing to the battery unless it was doing it's job.

[alantf]

[attachment=0:2wrf7ihu]Picture 169.jpg[/attachment:2wrf7ihu]Forgot to tell you....... Let the mechanic talk to me. I'm fluent in Bullshit. :yes: I've got the award to prove it. :crackup

[PimpS]

LOL

[PimpS]

Where is the ground connection?

[jonathan180iq]

Follow the fat wire away from the negative terminal on the battery. I don't remember exactly.
According to the wiring schematic, it's relatively close to the battery.

Section 7.8 of the service manual:
viewtopic.php?f=3&t=27 (http://gz250bike.com/forum/viewtopic.php?f=3&t=27)

[PimpS]

Thank you! The connectors for battery are shining, tommorow I'll check the grounding. Service manual is good and informative!

[PimpS]

Hello guys!

I got my gz back with new rectifier. Measurements were made (only with volt meter; rectifier, battery, stator or how it is called and all was in the right parameters). Since i got my gz back, i rode aprox. 250 km in two days. Do you think that this kilometrage or mileage is enough to bring out possible gremlins that may be are still hiding inside or are they spooked and gone to another place?

Bike is going well, i even think it goes better and smoother; i achieved new highest speed (just for seconds), also in a small downhill, it was 125km/h, that's about 78 mph. Also PimpSerS were more eager on flat terain (easily and faster to 100 kmph and uphill, usually i went to this hill, with the lowest speed 78 kmph (many times i changed from 5th to 4th), yesterday, after 2 hour ride it went lowest 85 kmph, in fifth all the time, on the top i went easily to 100 kmph.
One thing i noticed, that after 360km made since the chain and sprocket change, the chain got more slack (now it's about inch).
I hope i will be able to do it myself.
any recomendation, i believe i have to have torque wrench, or you guys do it by the feeling?

You've been all helpful a lot and take care and drive safe!

PimpS

ps:gone to the concert i have with my band El Kachon... Rn'r!!!

[alantf]

Hello guys!

I got my gz back with new rectifier.

Did you have your battery PROPERLY tested? - you never told us - I still say that the rectifier COULD NOT POSSIBLY be the fault. All I can say is that the original fault (possibly short circuit etc) must have cleared up. YOU'VE WASTED YOUR MONEY. I can't put it much plainer than that. Not much good us giving you the benefit of our experience if you're going to totally ignore us. Still, it's your money you're wasting! :sad: :tdown:

[PimpS]

Don't take it so personally, i'm not ignoring you. Load test wasn't made, that's true, but the rectifier (old) was showing some strange readings, it was like he was going on and off, I'm ignorant of electricity knowledge, it was like when getting hot, he turned off. Other collegue told me, that is strange, cause rectifiers are made, don't know how to say, let's say tough and over the usual limits, but it happens that they start to do their job faulty are not at all. He also mentioned me, that with his bike that he had, was also showing similar simptoms like mine, he changed battery, checked for short circuits, but the bike had a rectifier that was going faulty (on and off)... I'll have my battery checked too, not to please you, but me! Like you said it's my money that I'm spending. I'm not ignoring you, i'm thankful for all your input. Also i was warned not to press a lot the horn when not riding, cause usually the rectifier takes too much heat and it can break down (he said that on weddings, many times his friends burn the rectifiers when horning at turned on bike and not moving...

Stay cool and enjoy the ride! :)

[alantf]

Ah.... this points to what I said in one of my first posts - that there's the POSSIBILITY of an intermittent fault. Never known this to happen with a rectifier, before, but stranger things have happened. I'd still get the battery properly tested, just to give you peace of mind that the faulty rectifier hasn't caused any damage. Glad you've got it sorted, but you never told us about the "strange" readings on the rectifier - in fact, it appeared that you hadn't even tested it - so that's why we were so sure that it wasn't that. :)

[PimpS]

Strange readings were made before the instalation of new one. i didn't write it clear in my previous post. I agree with the peace of mind and testing battery, the electrician went for hollidays, i got to go to other, but was full. Week ahead i'll do that and tighten the chain.
It's new to me to run from mechanic to mechanic, ask you guys here, ask all my friends with bikes, get different information, opposite opinions... It's not just the matter of thrust nor competence, it's the wish to ride, bigger than anything else.
All these are new experiences to me, since i never put that much effort in repairing car, instruments that i play...
I'm sure you were all here... ;) If not, you are lucky!

[OldNTired]

[attachment=0:xgix4d2h]img080.jpg[/attachment:xgix4d2h]The only way to test a rectifier is to check the forward resistance of each plate, but I don't know what the resistance should be, and I don't think you're up to it. A rectifier is only (each plate) a gadget for allowing current to flow one way, and not in the reverse direction, so that the forward/reverse flow of alternating current is converted into the forward only flow of direct current.

Here's a simplified drawing of a little bridge rectifier that I made (using blocking diodes) so that I could fit a 12v dc buzzer to our 12v ac door entry system. If you follow the path, each way, from the ac to the dc, you'll see that in each case, current must flow from left to right across the dc terminals in each case. The diodes simply let the current flow in the forward direction, but not the reverse. You can see from this that if any diode went faulty, then we wouldn't get true dc across the dc terminals. That's why I said that your rectifier can't possibly be faulty, or the mechanic wouldn't have got dc at the battery terminals. there's really no need to test - you're either getting dc or not.

By the way........sounds like the mechanic's trying to baffle you with bullshit.

Sorry, but I can not agree. With mine, even though the rectifier was bad, I would get between 5,8VDC and 12.3VDC with the engine running. And I positively remember checking the diodes with a diode tester (had to borrow my neighbors). The procedure is, I think, in the manual. :)

[alantf]

Yes, but he said that the mechanic tested the battery with the engine running, and it was fine. From this, we took it to mean that the mechanic put a voltmeter across the battery terminals and got a consistently high voltage reading. This piece of information was what pointed to a good charging circuit, and the possibility of a battery problem. It was only after he had fitted the new rectifier that he mentioned that they had tested the old one and got weird readings. Seems like we were trying to help with the wrong information. This is the problem, over the internet, when you can't do your own tests. :)

[OldNTired]

Yes, but he said that the mechanic tested the battery with the engine running, and it was fine. From this, we took it to mean that the mechanic put a voltmeter across the battery terminals and got a consistently high voltage reading. This piece of information was what pointed to a good charging circuit, and the possibility of a battery problem. It was only after he had fitted the new rectifier that he mentioned that they had tested the old one and got weird readings. Seems like we were trying to help with the wrong information. This is the problem, over the internet, when you can't do your own tests. :)

My apologies! I missed the part where the mech tested with bike running with a consistent reading.
I agree with the difficulty of trying to diagnose without being there. And it gets worse when the 'facts' keep changing! :)

[PimpS]

Ok, np! I have another question:
Yesterday i haven't checked, but in the morning i saw that the rear wheel, when it was adjusted chain, i saw difference between the marks for rear wheel, it's not a lot, just a 1 milimeter less on the right side... Should i adjusted alone, or leave it that way? I think i would be able to do it, since i saw it. I think it would be enough just to loosen one screw (right one and do a bit of tightening)... Do I need a torque wrench, or do I just tighten as much as i can, The main scre i mean.
Thanks for replying!

No problems in cornering though...

[Water Warrior 2]

Ok, np! I have another question:
Yesterday i haven't checked, but in the morning i saw that the rear wheel, when it was adjusted chain, i saw difference between the marks for rear wheel, it's not a lot, just a 1 milimeter less on the right side... Should i adjusted alone, or leave it that way? I think i would be able to do it, since i saw it. I think it would be enough just to loosen one screw (right one and do a bit of tightening)... Do I need a torque wrench, or do I just tighten as much as i can, The main scre i mean.
Thanks for replying!

No problems in cornering though...
1 millimeter isn't a lot but it may affect chain and sprocket wear in time. If you saw it done once you can probably do it yourself now.
You need to start from scratch with the adjustment. Loosen both adjusters a bit. One full turn should be adequate. Loosen the axle. Try to remember the amount of force needed to loosen it and use the same amount to eventually tighten it. You will get the idea with time.
Now that the axle is loose just kick the rear tire forward until the chain is slack or stops at the adjusters. Slowly tighten both adjusters to match the same hash marks on the swing arm. I usually do a 1/6th turn of the adjuster for a simple reason. The adjusters have 6 sides and are easy to see. Do an adjustment, check the chain slack and hash marks. Repeat until you feel the chain is correctly tightened. Snug up the axle a bit. Check hash marks again as I have experienced axle movement when tightening an axle. If it is good with a snug then tighten with some force and call it good.
Others will drop in and add their info and suggestions too. It's all good. What I will miss some one else will clarify and make things right.