Oil Warning/Engine RPM Reduction/Powerhead Oil Tank Sensor/Oil Viscosity

I have an '04 2301 WA Striper with a '04 Yamaha OX66 200 HP 2 Stroke outboard. This week after the engine ran fine all summer, I had the low oil warning buzzer come on and the motor drop to 2000 RPM to conserve oil. I knew my oil level in the remote tank was fine as I had filled it two days before and checked prior to departing the dock and it was 3/4 full. After limping back to the dock @ 1800 rpm I removed the cowling to find the oil level in the power head oil tank was below the lower limit of the two lines marked on the powerhead oil tank. I figured that the liftpump on the remote tank had gone bad but when I took the sensor out of the powerhead oil tank the lift pump on the remote oil tank kick on and pumped the oil back to the upper limit. However after I ran the engine for a shakedown, I came back to port and found the oil to be between the lower limit and the upper limit on the powerhead tank. My question is do I still have a problem or does the lift pump only kick on after the oil has reached the lower limit as indicated by the two lines marked on the powerhead oil tank? The sensor appears to be good as it does kick the lift pump in when taken out of the tank and the float allowed to drop to the bottom of the sensor. The owner of my marina felt that I might have a problem with the viscosity of the oil as the temperature had just dropped below freezing for the first time the night before and that this was possibly causing an issue with the float on the sensor not floating properly. Also I had used a generic TCW3 oil instead of the YamaLube since my dealer was out of YamaLube when I filled the tank the day before. Any ideas, I thought about pumping out the oil in both the powerhead oiltank and the remote tank and replacing with YamaLube if this is the issue. Please advise if anybody has had this same issue or has any ideas. I'd like to get back out on the water while the Blues & Striper fishing is still hot and heavy as it's been here in NJ over the past three weeks.

Thanks,

PRumsey
The Professor
'04 2301 WA Striper
'04 200 HP OX 66 @ Stroke Outboard

[boats.net]

Do you have Yamaha gauges with oil level lights? Which light was on when warning was on? Was the oil filter dirty when you removed engine oil tank sensor? After you removed sensor and oil started refilling did it take more than a minute to fill up?

I don't see any lights that come on though it says in the manual that there should be three lights, green, yellow and red. None lit. I have Yamaha guages that are LED with levels, the levels blinked when I took the sensor out and the buzzer sounded. I don't see any oil filter inside the powerhead tank when I took the sensor out. The oil in the power head tank is not dirty. Yes it took more than a minute for it to fill and stopped when it reached the upper limit marked on the outside of the powerhead tank. I read in the seloc manual that the lift pump will operate for 3 minutes before cycling off. Though I didn't time it this was about the amount of time it took to go from the lower limit marked to the upper limit mark on the power hed oiol tank. Any ideas or help would be greatly apreciated

[jb123]

have you replaced filter on sub tank ??

I have not replaced and am not sure where this is located. I'm assuming in line between remote tank and powerhead tank and not under cowling of the engine? Please advise

[jb123]

on sub tank and is most likely slowing flow To main tank. with hi demand a clogged filter may not allow enough flow.