1981 GS750E oil light on

[drewandkellie]

I just rebuilt the carbs on an 81 750E with 5K original miles on it. It had been running only on choke, the bike is completely stock. It runs great now but the oil light is on. I shut it off Changed the oil and filter and tried again. Still the oil light is on. It didn't do this before the rebuild, and the motor sounds fine. I checked the oil window when I started it and the oil pulled down like the oil pump was pumping it, but I'm nervous to run it again. Could I have a broken a wiring connection from the carb removal? Is there any way to check before I move on?

[Loose Seal]

Here's an easy way to tell...and something you should do anyways.

http://www.thegsresources.com/_forum/showthread.php?t=125075&highlight=oil+pressure+gauge

[BassCliff]

Hi Mr. drewandkellie,

Is the light on even when you rev it up? It's possible that you have a connection issue. Check the wire to your oil pressure send unit. Also, if your idle is too low the oil pressure may fall below the cutoff point. Keep in mind these are low pressure systems anyway.

Thank you for your indulgence,

BassCliff

[76FJ55]

Keep in mind these are low pressure systems anyway.
BassCliff

Actually the 81 GS750 is a plain bearing crank so the pressure is much higher than the older roller bearing cranks. Here's what I would do to trace the problem.
Remove the oil press switch cover located on the oil filter cover, then remove the lead from the oil pressure switch. Now turn the key on (do not start the bike) and look at the oil light. if the light is ON while disconnected from the switch you have a short to groung in the wire between the switch and light. If the light is off touch the wire to ground and verify that the light comes on. If it is off when disconnected and on when grounded the indicator system is working correctly. If you can think of an easy way to pressurize the switch you can test it by checking continuity between the body and the wire attachment. the switch should conduct with no pressure and be open when pressurized. Reinstall the wire on the sensor but don't install the cover (you may need to use a couple extra washers to get the oil filter cover nuts to tighten) now start the bike and watch the oil ligh it should go out when the bike is running if it doesn't and you have verified both the switch and the circuit the oil pressure may be low.