The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: MR.E on September 25, 2011, 01:54:04 PM
-
Now then
Can anyone tell me where the alternator is on the bike please?
I ain't looked yet, to be honest, but are they easy to repair or should I just buy a new one??
Thanks
-
The alternator is located under the front cover.
The cover is held on by two allen head type fasteners .
There a 'hot' connections under the cover, by that I mean they always have battery power available to them, regardless if the key is in the ignition or not .
Remove one of the battery cables and secure it out of the way .
The cables are old and have taken a shape over the years, that will allow them to move back if they aren't secured by a ty rap or something similar .
The alternator is easily replaced, you can replace the rotor, stator, diode board rectifier, or regulator itself, not a 'package' like on a car or truck .
-
Yes listen to Bob, you dont want to fry the board disconnect the battery first. Underneath the alternator you will see the "Bean can" 81 should be electronic ignition but could be a points unit.Did you sort the carbs out?
Lou
-
But , I have to admit, I had my '81 R65 over 20 years before I learned this :o :o ::) ::) ::) !!!!!!!!
-
now then
cheers for the advice, i'll be heading down in 5 mins to strip it off.
If it's not charging what might i need to replace?
it's an electric start 81 model, but it's not charging on ride outs & by the end of the day i usually have to bump it off down the road.
Lou, think the carbs are ok, not had much chance to test em, been buying the mrs a house for when pip's born!!
looks like with the decent weather this week i'm gonna get some time to finish it off.
thanks
-
... If it's not charging what might i need to replace?
... it's not charging on ride outs & by the end of the day i usually have to bump it off down the road.
Check the carbon brushes - confirm they are not worn down so far that they no longer are making contact with the rotor. If the "pigtail" springs are contacting the brush holder, that may be a clue of excessive wear. You might try lifting the springs, insert a small plastic or wood spacer, replace the springs and see if you get a charge.
Brushes are in two positions. The stator ring must be removed to service the rear brush.
Check all wiring terminals for security. Be sure negative battery cable is disconnected prior to messing wit' da 'lectics.
Also, confirm GEN lamp is not burned out.
Monte
-
Probably a bit too late for this, but before you take anything apart, you need to do a bit of troubleshooting .
First, when you turn the key to the 'ON' position, does the red "GEN" light come on.
If it does, attach the leads of a multimeter to the battery, start the bike and bring the rpm's up to 3500-4000 rpm, voltage should be in the 14 volt range, it should be higher than the battery voltage before you started the engine . .
-
now then
got sidetracked so haven't started yet!
the bike no longer has the rev counter fitted BUT the red gen light used to come on when i turned the key, then went out whilst i was riding.
I've not tested the battery with a meter, whilst it's running, so will do that tonight.
Thanks
-
Well, there's your problem! :)
The alternator needs the electricity from that light bulb in the tachometer to function. Without it, no voltage is generated!
-
Well, there's your problem! :)
The alternator needs the electricity from that light bulb in the tachometer to function. Without it, no voltage is generated!
you pulling my leg??
-
No he isn't !!!!!!!!!!!!
Look around the connector that went on the tachometer, there should be a light blue wire, connect that blue wire to a solid brown wire, solid brown wires are grounds or earths on BMW motorcycles .
Once you do that, you should have a functioning charging system.
The "GEN" light has an important function on these 'farm implements', it completes the circuit from the voltage regulator to the alternator rotor !!!!!!
-
well bugger me!
thats crazy stuff!
& it saves me loads of trouble.
Thanks lads, once again!
-
The "GEN" light has an important function on these 'farm implements', it completes the circuit from the voltage regulator to the alternator rotor !!!!!!
Once you know how to 'read' the charge light, you can pretty well tell what's going on with the alternator. It's really a misnomer to call it an idiot light - probably named that by one. ;D
-
The "GEN" light has an important function on these 'farm implements', it completes the circuit from the voltage regulator to the alternator rotor !!!!!!
Once you know how to 'read' the charge light, you can pretty well tell what's going on with the alternator. It's really a misnomer to call it an idiot light - probably named that by one. ;D
will it be worth me fitting a light to it, so i can 'read' it??
-
I think so. I like to know what's going on with the charging system so have either the bulb or gauge, or both. Not sure if there's any other negative impact running a hot lead straight to the alternator, rather than through the bulb. I think the bulb does limit the current to the alternator, which limits overall output.
-
Without that indicator light, you have no idea if the charging system is working properly .
One of our members here (Monte) installed a Vapor instrument cluster, it's all LCD's, he put a light in the 10mm hex in the steering head nut, ran the wires from the bottom this was for an oil pressure light, the steering stem is hollow, just an idea .
Don't use an LED type bulb it needs to be an incandescent, it doesn't have enough resistance to properly operate the voltage regulator circuit .
-
There is an easy DIY solid-state replacement circuit that can be substituted for the GEN lamp. It can also be fitted as a backup system in the event your gen bulb goes Tango Uniform.
Rick Jones used to sell the item but I notice it is no longer shown on his web site catalog. So easy to create, perhaps sales were slow.
The Snowbum has all the details... naturally. http://bmwmotorcycletech.info/genlampresistor.htm
I have the circuit on both my R65s. The '83 still has the stock cow's tongue and instrument pod with the GEN lamp. The '81 runs only the modified GEN lamp replacement circuit.
Everything you'll need is available at the Shack.
Monte
-
Cheers for the info, I'll look at it tomorrow
Just in the garage with the bike, if I plug a light on the end of the blue cable (& a brown) it doesn't illuminate but it does if I touch the black (& brown).
Does that mean it's Knackered anyway??
-
If you are talking about the black wire at the tachometer connector, that wire comes from the ignition coil to operate the tachometer .
A solid brown wire, without any colored spiral band on it should be a ground, or earth wire .
Could very well be that you other problems, you just need to go about it in a methodical manner .
-
Hello
Yep, a solid brown and the black in the tacho block.
With the blue it didn't light & when the brown and blue were connected there was no difference on the charge to the battery ( seemed to stay at 12.8v on the meter)
Any recommendations of what to tackle first?
Thanks
-
You need to check the blue wire from the diode board to the tachometer connector for continuity .
The blue wire goes through a two wire connector somewhere in the wire harness, then goes to the diode board at the front of the engine under the front cover.
-
hello
so i found the blue & brown wire, i connected them to one of the dash bulbs - so i'd know if the altenator works when i start looking about - but as the weather is so nice i went for a ride today & whilst out on the ride the bulb lit up!
I'd rode allday without the lights on then 10 mins after riding with the lights on the bulb comes on.
It doesn't come on when i turn the ignition on & if i'm at traffic lights for a while it'll go out but come back when i set off.
SO is this normal for the R65??
thanks
-
The normal "GEN" light operation on an R65, when you turn the key to the "ON" position, the light should come on .
After starting the engine, the light will go out when the engine rpm's get to around the 1400-1500 rpm range (all bikes are different, some go out earlier) .
The light should stay out until you bring the engine rpm's back to idle, then, it may stay on bright, or sometimes flicker or fade out then come back on .
So, above 1400- 1500 rpm's or there abouts the light should always be out .
-
Hmmmmm
I've no idea then!
On idle it flickers and goes out eventually
But if I set off it comes back on and stays on for the duration
Is that an indication of a fault?
If not i may just replace the interior of the alternator!
Cheers
-
If the light is on, it's indicating that the charging system is not charging .
You need to find out what's wrong, before you start replacing parts, it may be a wiring problem and replacing parts may be a futile and expensive effort without fixing the problem !!!!!!!
-
hello again
I've just taken the altenator cover off the inards bit that bolts on the end of the shaft.
is there a tool/correct way to pull of the old spinning bit (sorry, you may notice i lack the knowledge of the correct mechanical terms!!)
thanks
Elliott
-
The rotor, that's the part bolted to the end of the crankshaft, you need a special tool to remove it, don't try prying or beating on it .
The tool isn't expensive, here in North America, they are about $5US.
-
A word of future caution: when replacing the stator (the static - non rotating part of the alternator) be extremely careful to get it started evenly into its mounting spot. If it gets cocked and it's not noticed, then the torque of the mounting screws can break the aluminum housing. Not a good thing at all!
The part you're removing is called - get this... the ROTOR. :-) Because it rotates. Must not have been an engineer that named these things.
I've seen rotors removed with gear pullers, and they get a bit damaged in the process. Not enough to make them unuseable, but still not a good thing. The proper tool is a very hard bolt something like 80mm long with threads removed half way to the end, so it's only got threads from the head to half way. Thread it in, bottoms out against the crank, and POP!, it's loose.
-
A word of future caution: when replacing the stator (the static - non rotating part of the alternator) be extremely careful to get it started evenly into its mounting spot. If it gets cocked and it's not noticed, then the torque of the mounting screws can break the aluminum housing. Not a good thing at all!
The part you're removing is called - get this... the ROTOR. :-) Because it rotates. Must not have been an engineer that named these things.
I've seen rotors removed with gear pullers, and they get a bit damaged in the process. Not enough to make them unuseable, but still not a good thing. The proper tool is a very hard bolt something like 80mm long with threads removed half way to the end, so it's only got threads from the head to half way. Thread it in, bottoms out against the crank, and POP!, it's loose.
Hello
cheers for the info.........the rotor hey!!!
think i've some rods that'll do that job then.
What is the name of the rotor cover, with all the connectors on it?
Cheers
-
It' called a stator .
The tool that's used to remove the rotor, is hardened, if you use threaded rod, most likely it will bend inside the crankshaft .
Then you've got a real job to get it undone !!!!!!!!!!!!
-
Yep, it's called the stator - it's static (doesn't rotate).
As with a lot of things airhead related, the rotor puller bolt is simple, yet complex. Contradictions abound!
One of the ways suggested to remove the rotor is to have a bolt about 40mm long that will thread into the rotor. Then have another rod 30 or 40mm long, but smaller diameter that will bottom into the hole in the crank. Then with the rod installed, screw in the bolt, which then presses on the rod and forces the rotor off.
Well, that works sometimes, and sometimes not. And it can bugger up the threads on the end of the crank.
The best thing is a grade 11? bolt something like 80mm long with half its threads ground off. I've gotten metric allen bolts from the hardware store and either ground off the threads with the grinder, or now that I've got a little lathe, with that. Much more fun with the lathe and turns out much nicer. But the bolts themselves can cost two or three bucks before any alterations.
-
ey up
not touched the bike in a while!!
got the old rotor off the other day, seems the seal behind the rotor was leaking so i replaced that & the bean can O-ring.
The stator's plates (on the inside of the stator) had a good degree of black on them - i assumed it was oil, gave them a good clean up & put it all back together.
I turned the key to see if the gen light would come on, but it didn't!
Though i haven't run it yet with the new rotor fitted, will i need to run it for the gen light to start working?
If not could there be something i've missed??
Thanks
Elliott
-
My first guess, is that you have the fiber insulating washers that hold the brush holder in the wrong position .
The terminal with the black wire needs to be insulated from the alternator stator case, if it isn't, the power from the voltage regulator goes right to ground or earth and the alternator will not work .
If you didn't have the brush holder off, swap the wires on the two terminals on the brush holder and see if that helps .
As soon as you turn the key to the 'ON' position, the 'GEN' light should come on .
-
If the wiring was incorrectly connected, DF attached to a ground point for instance, then the light should come on.
Besides, the brush holder shouldn't have to come off when removing the stator to replace the rotor. Right?
Ground the DF connection at the alternator (ignition on) and the charge light should come on.
If not, the next thing to check is the light bulb. Otherwise, it's a broken wire, bad connection, or no power to the circuit in the first place.
-
My first guess, is that you have the fiber insulating washers that hold the brush holder in the wrong position .
The terminal with the black wire needs to be insulated from the alternator stator case, if it isn't, the power from the voltage regulator goes right to ground or earth and the alternator will not work .
If you didn't have the brush holder off, swap the wires on the two terminals on the brush holder and see if that helps .
As soon as you turn the key to the 'ON' position, the 'GEN' light should come on .
now then
not been on this for a while
The plate never came off but there are nylon washers on the black cable side!
still no light!!!
-
Ground the DF connection at the alternator (ignition on) and the charge light should come on.
done, assuming the DF conecction at altenator is on the brush plate black wire?!
but still no light!!!
Thanks
-
Sorted it thanks to Tez at motorworks pointing out i'm an idiot!!
Thanks for all you help
Elliott
-
Let's see if I understand this: Tez said "you're an idiot" and then the system started working correctly?
Somehow I think that's not what happened. ;)
So what fixed it? What was wrong that's not straightened out?
-
here's some helpful reading .....
http://www.5united.net/html/charging.html
Cheers,
Carl
-
Let's see if I understand this: Tez said "you're and idiot" and then the system started working correctly?
Somehow I think that's not what happened. ;)
So what fixed it? What was wrong that's not straightened out?
Well i suppose you're right!!
Since september 2011, when i altered the wiring loom i had a problem with the GEN light, it did flicker once i'd altered the loom though.
So i started stripping the stator & replaced the rotor & brushes but nothing, i spoke to Tez yesterday who went over the wiring diagram & he pointed out that the gen bulb doesn't have an earth (i wired an earth to it) but instead has 2 lives - 1 from the diode board & one from the altenator!!!
So with switching the cables in a 10 min job it's fixed!!
If only i'd read the right wiring diagram!!!!
-
"If only i'd read the right wiring diagram!" –Mr.E
Oops [smiley=deal2.gif]
-
Excellent! I understand now. Well done getting that sorted - and it follows that old trouble shooting rule of thumb: look in the last area that was worked on.