Re: 2003 envinrude 135 hp no oil light
No Oil alarm is an indication that the OMS pump is not seeing movement of the oil into the gas line. You need to run premix until you sort this out.
I would pick up an OEM Service manual. Marineengine.com sells them as do other places. Have your model number handy. There is a troubleshooting procedure to test the OMS pump and the no oil sensor and wiring.
This alarm is as serious as it gets. If it is not a false alarm, your engine is running w/o oil, which will cause greate damage.