Author Topic: Oil with altenator !?  (Read 205 times)

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Offline Ted Bundy

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Oil with altenator !?
« on: December 30, 2019, 02:55:54 PM »
Hi everybody. I'm brand new to this great forum and pretty new to my XS500 -76. I've had 2-strokes all my life.RD350-400, kawasaki triple and suzuki GT380. This yamaha is my first 4 stroke.

I started with the usual carb cleaning, oil change etc, when I discovered a charging problem. No power comes to the battery :(
Could be the rectifier, but as far as I can tell with my meter, its OK. I unscrewed til LH round panel that covers the stator/altenator and oil came out of the buttom screwhole (has 2 screws). I have never seen oil around the alternator before?

Is that normal?  :o
I mean it's still an electric component. I haven't dismantled it yet, but I will soon.

The dipstick for the oil goes directly into the sealed compartment where the alternator is located and the balancer chain must be lubricated from something, so I guess it's normal with oil in there?

Just need some peace of mind... (oil is good.....but in the right places)


I read that the lubrication system on these models are quite advanced.

Does anyone know, I would appreciate it very much.

Happy new year to all of you from Denmark  :)

« Last Edit: December 30, 2019, 02:59:37 PM by Ted Bundy »
Yamaha XS500 1976

Offline lumpy252

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Re: Oil with altenator !?
« Reply #1 on: December 30, 2019, 03:57:53 PM »
Hi there the alternator does operate in the oil , it is a field coil alternator with the windings fixed on the inside of the engine cover on the left hand side (as sitting on the bike). Current is made by the alternator/flywheel spinning inside these windings . Try the tests for the charging system described in the electrical section of this site, the feeler gauge method is worth a first trial. A thin blade when held close to the left casing over the alternator should slap against the case when the ignition is turned on , as this should magnetise the alternator if all is well .

Offline lumpy252

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Re: Oil with altenator !?
« Reply #2 on: December 30, 2019, 04:28:57 PM »
Hi again, and welcome, when you refer to undoing two screws on the round cover to the alternator housing this will not help as this will uncover three Allen bolt heads which secure the field coil windings . These need to be left in place . The only way to access the alternator is to drain the oil and then remove the large left hand engine case . You do not need to do this until the electrical outputs are checked though.

Offline CrouchyUK

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Re: Oil with altenator !?
« Reply #3 on: December 30, 2019, 06:44:42 PM »
If you take the main cover off, then it may be worth checking that those 3 bolts that hold the field coil into the cover have seals under the heads?  There should not be oil behind the round trim plate.....
1975 Honda CB200T (2) - 1975 Yamaha XS500B (2) - 1976 Yamaha XS500C
1977 Yamaha RD400D - 1977 Yamaha XS500D - 1978 Honda CB550K - 1980 Honda CB400N
1980 Honda CB900FA - 2000 Kawasaki ZX6-RG2 - 2002 Suzuki GSX-R1000K2

Offline Ted Bundy

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Re: Oil with altenator !?
« Reply #4 on: January 01, 2020, 10:32:33 PM »
Thanks for the tip! :) Just to make sure. What you are saying is that stator/altenator are fixed to the back/rear side of the engine cover and operates in an "oil bath".
Yamaha XS500 1976

Offline lumpy252

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Re: Oil with altenator !?
« Reply #5 on: January 02, 2020, 12:43:51 AM »
Yes thats right these engines are different to the two strokes you list as your previous bikes , as is already obvious to you. I will load some photos of the inside of the left hand casing which will help. The rotor or flywheel sits inside the gap between the windings attatched to the inside of the engine case. Which is all sitting in the engine oil.

Offline lumpy252

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Re: Oil with altenator !?
« Reply #6 on: January 02, 2020, 12:48:41 AM »
this one is the inside left casing

Offline lumpy252

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Re: Oil with altenator !?
« Reply #7 on: January 02, 2020, 12:57:32 AM »
I have replaced that loose starter chain since the photos were taken  ;)

Offline Ted Bundy

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Re: Oil with altenator !?
« Reply #8 on: January 02, 2020, 10:42:57 AM »
Thanks a lot.  :D I tested the alternator and there is a short circuit. Ordered "new" parts today. I always google everything before I take things apart, so I wont make any mistakes. With your help :) It's became an easy operation.

Thanks again  :) :) :)
Yamaha XS500 1976

Offline lumpy252

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Re: Oil with altenator !?
« Reply #9 on: January 02, 2020, 10:57:37 AM »
That is good to hear , I wish you well with your project....