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I have a 130 Sport BW with a 2004 40 hp Mercury engine. The "low oil" alarm buzzes when the oil tank is full. I've disconnected the alarm plug on the side of the engine to quiet the alarm. I'm getting the boat ready to sell and I'd like to fix the problem. I was told by the service advisor at the mariner where I have the engine serviced that I can't just swap the tank out to fix the problem, but that when you replace the oil tank you have to bleed the oil injection system. Is this the truth??? Has anyone experienced this problem and if so do you really have to bleed the oil system? I would like to do this myself if possible. So any advice would be much appriciated.

Thx in advance,

Geoffrey

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Any time oil lines or oil tank is replaced the oil system needs to be bleed.

It is also recommended to run the motor on mixed fuel to make positive that the oil is being consumed and used from the new oil tank.

I replaced my oil tank once and did the above.
I put a line on the oil tank level and went for a cruise.
When I returned you could positively tell the oil was down below the line indicating the motor was using oil from the new tank.

I temporarily used a portable 6 gallon tank with mixed fuel for the above test.
Yes, the motor may smoke more during this test as it is using double the oil but it saves the motor in case the new oil tank isn't working properly.

The above is the recommended way to check the new tank or lines.

Good Luck.

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Thank you Joe for the reply, and it sounds easy enough. So is that the "standard" way you "bleed" a fuel injection system?? Has anyone else used this method??


Geoffrey

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There is a $20 sensor that needs to be replaced in the exterior bottom of the tank. Loosen the tank attachments to tilt the tank to gain access to a screw the holds the sensor in place. It works on proximty to an internal float in the tank that is molded into the tank. When the oil level gets to low the magnetic float trips the sensor and sends a signal to the warning module and sounds the warning horn. No need to drain or replace the tank. I went to marineengine.com and just picked serial number range OG to OT, you need to verify your serial number to make sure.

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I should give you a little more insight into this. When you remove the switch, check the switch with an ohm meter connected to the two wires. If there is continuity the switch is bad, if it is open (no continuity) the switch is good and the issue is with the warning module. I highly recommend a replacement module from CDI electronics, lower priced with a warranty, made in USA. The only reason to replace the tank is if the magnetic float is stuck down in the tank, there is no access to this float since it is in molded chamber in side the tank, I have seen the tanks removed, emptied and cleaned with gas or safer to use kerosine, filled about a 1/3 of the way up and shake the solution around to break the float loose. The bleed process described is accurate. One addition to this is when you refill the tank with oil, crack the bleeder screw on the side of the oil pump to purge the air out of it and oil will start to run out of the pump. Tighten the bleeder screw. Next, disconnect the throttle controlled link arm the connects to the oil pump which will allow full 50-1 oil flow at idle, mark the tank and the oil level should start to drop in about 10-15 minutes of running on your flush muffs if you want to do this in the driveway instead of launching and running the boat. Then just reconnect the link arm back to throttle linkage and you're good to go. The linkage is ball and socket attached so it just pops off with a little effort and pops back on after your test. If you want to launch and run, just run the engine on the premix without disconnecting anything, but still bleeding the pump first.

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Thank you Fitz for the help. My motor ser# is OT953673. So I'm guessing the sensor you speak of is #13 on this page:

http://www.boats.net/parts/search/Mer...parts.html

Geoffrey

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Correct, just do the test on the current switch with it removed before you purchase the new one.

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Ok the magnet is not stuck on the bottom of the oil tank and and Ohm test indicates that the probe going up into the tank is also good. This leave only the warning module as the possible culbrit. How would I go about changing this?? Is it located in the throttle assmbly?? Thx for all the help in this matter, boat marinas repair bills scare the hell out of me.

Geoffrey

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Should be located on the starboard side, looks similar to the rectifier/voltage regulator. Your oil tank and heat sensor wiring should be plugged into it.