Bike just died

[benita]

I've got one for you.Yesterday I was diving my 83 r65 and it just quit on me.Tried the start button ,nothing ,not even a sound.got it towed home.First thing I checked was the battery to see if it was discharged by putting a automatic trickle charger on it.(the one that lights up green when fully charged)took a whole day until it was recharged.The thing that gets me is that the discharge warning light always worked fine , until it died, now it doesn't work at all.Tried to turn on ignition switch to test all lights in tach,all worked except charge light .Tried to check the bulb in the tach ,but it was ok when I tested it,even bought a new one put it in tach still did not work when ignition switch was tried. Bike starts and runs fine for a short trip, five minutes or so.But am afraid to take it on a longer trip in fear of discharging the battery again and being stranded.what do you guys think.Voltage regulator , stator ,rotor,diode board, stator brushes ?    

[Bob_Roller]

To quote Rick Jones book on airhead charging systems, 'a break in the rotor winding will prevent the bulb from lighting'.

I think I would test the rotor for continuity.

Should have in the neighborhood of 3.4 ohms.

[nhmaf]

Bob is right - if you are sure that the bulb is good and the connections inside the tachometer/bulb socket/wiring board are good, then it could well be either a bad rotor (broken wire) or it could be bad/broken/worn brush connections or issue with the slip rings on the rotor, which could also interrupt the circuit.   Either a burnt bulb or break anywhere in the circuit (which could also possibly be a totally trashed voltage regulator or bad connection at the regulator) or loss of continuity in the rotor & brushes will prevent charging from happening and show a dark bulb.

If you have a multimeter and are handy with circuit troubleshooting, I'd start up at the tach first looking for loss of continuity in the circuit.  But you'll probably do well anyhow to check the rotor and brushes anyway.

There is a modification where you can put a 470 Ohm, 1 Watt resistor (1/2 Watt resistor can do in a pinch, but definitely do not go smaller than 1/2 Watt)
in the tachometer and solder it to the connections that feed the bulb.  This will allow the circuit to work & charge the battery even if the bulb breaks on you while on the road - but it won't solve the charging problem if the issue is elsewhere/not the bulb.

[Bob_Roller]

There's a check of the wiring from the the slip rings up to the indicator light.

With the front cover off of the engine, turn the key to the run position, and then place a metal object regular screwdriver or the like across the slip rings, and if the circuit back to the bulb is good, the charge light should come on .

[benita]

yes,Bob,where exactly do you place the screwdriver?

[Bob_Roller]

You place the screwdriver to make contact with both sliprings, you may get a slight arc when you do this, but it should be barely visible, as this is excitation voltage from the regulator not like a dead short on a battery lead.

[benita]

Yes,today i tried what you said by jumping the two rings of the rotor with a screwdriver.Charge light came on.Next I ohmed the rotor,open circuit.Looks like I'll be needing a new one from motorrad elektrik.Tried calling them today to order one and as luck would have it, they went to a ''chicken run'' till June 2.
                                                Bill

[Bob_Roller]

At least you have it sorted out, only about an hours worth of work to replace the rotor.

Before you order your rotor, check the brush length, I think a new brush is 17mm.

 Also if you don't have a rotor removal tool, you need to make one, or order one from Motorrad Elektrik .

[benita]

How can one make a removal tool?I allready bought the brushes yesterday when I got a spare charge light bulb.

[Bob_Roller]

All the tool is, is a bolt and I'm not 100 % sure, but I think it is the same diameter and thread of the allen head bolt that holds the rotor to the crankshaft, the last inch or so of thread is removed to make it a bit smaller, to fit all the way down into the hole in the crankshaft and bottom out, so you start pushing the rotor off of the tapered area of the crankshaft where the rotor sits, as you tighten up the removal tool.

Motorrad Elektrik has the tool for about $6, they do state that the tool is hardened, so I don't know if that would make a difference or not, using a bolt instead.

[benita]

Yesterday I made a puller tool by cutting a 1.5''chunk of .250'' allen wrench.Inserted said peice,then tightened the rotor bolt on top of that,presto... rotor off.Found a motorad elektrik replacement rotor that my local BMW dealer happened to have.Installed today, works fantastic.I'D like to thank you guys for pointing me in the right direction in diagnosing the problem.
                                               Bill

[Bob_Roller]

Good to hear that you had a quick fix, and didn't have to wait a couple of weeks for a replacement part.

Get out and ride !!!!!

[nhmaf]

Good Job !  It is always satisfying to be able to work on and fix these bikes yourself, isn't it?!!!

I love it when things work (or don't work) the way that we expect them to!   I wonder if our batting average is close to the "car talk guys"?

[msbuck]

I wonder if our batting average is close to the "car talk guys"?

We're at least as much fun!