1980 Yamaha XS650 oil leak and electrical issue (with video explaining)

JaxShane650

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Video showing and better explaining issues -
Hello, this is my first post on this forum and I hope y'all can help me out with this one. I have recently acquired a 1980 Yamaha XS650 that was not in too bad of shape. I'm new to motorcycles and never worked on one before, but I have experience working on cars, small engines, etc. The motorcycle had been sitting in a barn for some years and was supposedly rebuilt and restored before it was put away. I have been going through this motorcycle trying to get it road worthy and somewhat restored and have run into a few issues. The fist one, which is the more major problem, is that there is a pretty good oil leak coming from somewhere by the front sprocket. It is causing a good amount of oil to come out at times and has me concerned. The second issue is a electrical related one having to do with the blinkers. I get the left side blinkers to work flawlessly, but when I switch to the right side blinkers the rear one will blink fine (sometimes) and the front one will not blink at all. I have already changed out the blinker relay and changed out all the bulbs out for good ones. I feel like it is a grounding issue, but have no clue where else to look or if that is even the problem. Any Ideas or troubleshooting things I could do would be much appreciated!
One more thing I almost forgot, is it normal for an XS650 not to be able to shift into neutral while running, but be able to shift into neutral while not running just fine?
 

5twins

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Your oil leak is probably nothing more than a loose countershaft sprocket mounting nut. Even with that folded up lock washer, they do come loose. It's also possible it wasn't installed tight enough to begin with. They need to be tight, really tight, to prevent oil leaks there. The torque spec for that nut is something Yamaha changed several times over the years, don't know why. Best seal is achieved by using the higher values they recommended for some years, 72 to 94 ft/lbs. I think they dropped it as low as 36 ft/lbs on some models.

The blinker issue could be a ground problem but could also be a power problem (lack of) to that right front unit. Does it's bulb light at all, just not flash? The grounds are separate for all the signals, just a ring terminal on a wire under the stalk mounting nut. You can check that, make sure the connection is clean and the other end of the wire connected (plugged in). The power wires for the signals are a dark green and a dark brown (called "chocolate"). Dirty and/or in poor lighting, they can look black. Maybe that non-working signal's power wire was mistakenly connected to the black ground wire hub instead of it's power feed.
 

JaxShane650

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Okay I'll try and see if tightening that nut stops that oil leak. Have any clue what size socket I need for it? If the problem doesn't stop after tightening I'm guessing the next course of action is to change out that seal somehow?

Thank you very much for the blinker tip. It was the power wire that was plugged into the wrong terminal and now the blinkers work flawlessly! The only electrical question I have left now is that is the light in the middle of the tachometer and speedometer that says head light, when is it supposed to be on and off? Because I have had the headlight in and out of the bike for testing and I'm not sure when that is supposed to be on or off.


Your oil leak is probably nothing more than a loose countershaft sprocket mounting nut. Even with that folded up lock washer, they do come loose. It's also possible it wasn't installed tight enough to begin with. They need to be tight, really tight, to prevent oil leaks there. The torque spec for that nut is something Yamaha changed several times over the years, don't know why. Best seal is achieved by using the higher values they recommended for some years, 72 to 94 ft/lbs. I think they dropped it as low as 36 ft/lbs on some models.

The blinker issue could be a ground problem but could also be a power problem (lack of) to that right front unit. Does it's bulb light at all, just not flash? The grounds are separate for all the signals, just a ring terminal on a wire under the stalk mounting nut. You can check that, make sure the connection is clean and the other end of the wire connected (plugged in). The power wires for the signals are a dark green and a dark brown (called "chocolate"). Dirty and/or in poor lighting, they can look black. Maybe that non-working signal's power wire was mistakenly connected to the black ground wire hub instead of it's power feed.
 

5twins

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The sprocket nut takes a 36mm socket. If you have a Sears nearby, it just happens to be the largest metric one they sell. That "headlight" idiot light is a warning light for if your low beam burns out. It shouldn't come on unless that happens. It works in conjunction with a silly '70s safety device Yamaha used to install called the reserve lighting unit. It's mounted under the seat on the frame brace just behind the battery. If your low beam burns out, it automatically switches the high beam on, but at a reduced voltage so it's not blinding to oncoming traffic, and turns that dash light on. It's fine if it's working right but today, 30+ years later, many of these units are crapping out. When that happens, you can have all sorts of weird headlight problems. Most of us just get rid of the thing. You have to jumper a couple wires in it's harness plug to restore normal headlight operation. Details are here .....

http://www.excess650.co.uk/tips & tricks.htm
 

mikeh36

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I don't know about anyone else but I've battled the no neutral while running forever. Mine is fine until the engine gets really warmed up then I have to fight it into 2nd the lightly tap into neutral. There's a clutch adjuster on the left side just behind the alternator (should have a little round cover you can pop off with a screwdriver). You just have to find the sweet spot I think (I still haven't). If you don't have a manual already I'd try to get one.
 
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