Bad Oil Level Gauge?

[savcap]

I've got a '89 Yamaha 150 (150ETXF). I always crank the engine before towing to the ramp. I was getting ready to put it in the water last weekend (after replacing the fuel filter head(!)). Cranked great, running fine for about 5 minutes then it started making an alarm. Seems to be a low oil alarm, but I'm not sure. I've cleaned the reservoir and checked to make sure that the pump is working (applied 12v and oil started coming out of the tube). The emergency pump on the engine block also pumps oil into the oil tank on the block.

I took out the oil level guage and put it on a ohm meter. It seems that if the float is at the bottom of the stick the switch should turn on. It only turns on if the float is in the middle of the stick. Seems that this might be the problem.

However, I'm not even sure that this is an oil problem. Will the oil light be a bright red? If it's not oil, what else would cause an alarm as soon as the ignition is turned on?

Thanks, and sorry for the long post.

[boats.net]

Overheat or low oil will activate alarm, the red low oil light should come on if it's low oil alarm which is when the engine oil tank oil level sensor float is at bottom os sensor. Middle switch in sensor does turn on oil transfer pump.

[savcap]

Overheat or low oil will activate alarm, the red low oil light should come on if it's low oil alarm which is when the engine oil tank oil level sensor float is at bottom os sensor. Middle switch in sensor does turn on oil transfer pump.

So sensor is working as advertised...

Are there no 'overheating' warning lights?

Is there a way to check to see if the engine thinks it's overheating? Perhaps a stuck thermostat or bad sensor...

[boats.net]

You can test the temp sensor as per service manual.