oil buzzers???and process of elimination

[scarab30/200]

new to this site,looking for a little help.evening all. sunday we were out on the boat about 15 miles off shore when a buzzer for the strbd engine went off. checked oil resivour and it was low,i manually filled with oil by using the override switch.all was good so we thought, for about 2 min. the buzzer sounded again,this time the oil was good.thought maybe temp problem,both engines had the same amount of water @each peehole.long story somewhat short.limped back in on one engine.did a check of the oil tanks ,engine and main tanks,both were full.did a test at the engine tanks,floats worked good on port engine.pump kicked on and off with the float@ the main tank.strbrd engine wouldnt come on by raising or lowering the float,but would come on by using the override switch on the engine.if i unplugged the float @ the harness and turn the ign swith on the pump would come on for 2 sec and shut off,no oil would be pumped to engine tank.but the port side would completely fill tank if permitted,using same process as mentioned before.can i diagnose any issuues by swapping main oil tanks temporarily? any and all help would be greatly appreciated greatly

[boats.net]

If you have Yamaha gauges then look at oil level indicators, if the oil level in boat oil tank becomes low or if oil level sensor is bad then gauge will show middle bar on oil level indicators and oil will not transfer to engine tank except with emergency switch. Check oil level sensor and wiring going to tank.

[scarab30/200]

boat.net thank you very much for your advice,it did help.so again thank you.got the oil pump tank situation taken care of.also found temp variance between thermo housings on strbrd engine. strbrd engine as follows @2.5 min outside thermo housing temp 145*.inside thermo housing118*.@ 5 min mark outside thermo housing125* inside housing116*. should there be that much diff between the two?pulled the thermos and ran for 2 min,w/ thermo covers in place temp on the outside cover was 157*inside thermo cover was 113*. port engine temp @ 5 min was 116* on each thermo housing. all of this was performed on the garden hose wide open,engines at idle.temperatures were read with hand held infrared temp gun. cuold there be bad water pumps? they were replaced apprx 80 hrs ago last year,yes oem parts were used.ordering new pumps and thermos tommorrow, will change this weekend ,wish me luck.any and all advise is welcomed and greatly appreciated.thank you in advance.

[boats.net]

You can't test water pump on garden hose, in most cases it will not supply enough water to engine. It is not uncommon to see different temp reading on each head, most engines thermostats don't even open until about 125 degrees.

[scarab30/200]

all parts have been changed. hopefully all ends well,well be lake testing tommorrow afternoon. thanks boats.net for rapid responses you are the man.