gas sending unit

[Baby Blue]

1998 Maxum 2800 scr
7.4l 454
102 gallon tank

does anyone know what the appropriate gas sending unit is for this boat and where to purchase one?
Boat is in storage an hour from my home so I don't have the info off the unit.
any info appreciated.
BB.

[mmwjr]

Typically one removes the sending unit and matches it a new one. They also sell units that have an adjustable arm so you can set it up to match yours. These can be bought online or at any marine store such as West Marine.


PS: don't attempt to replace it if the tank is full wait till you get down to 3/4 tank or less to ensure gas doesn't spill out.

[shrew]

Originally Posted by mmwjr

Typically one removes the sending unit and matches it a new one. They also sell units that have an adjustable arm so you can set it up to match yours. These can be bought online or at any marine store such as West Marine.

PS: don't attempt to replace it if the tank is full wait till you get down to 3/4 tank or less to ensure gas doesn't spill out.

Ditto. This item is so infrequently changed, I'd be surprised if anyone has this info. on hand. It will get replaced every 15 - 20 years, or more in some cases. I'd bet the majority of folks have never had to replace one ever. As for the 3/4 full tank, this would especially be the case if the boat is not sitting level. If the stern is a little low, fuel will be sitting more toward the aft end of the tank. Remember that it isn't sending fuel to the carb, it is only sending a reading to the guage. This can be replaced in the water.

[Phillbo]

Originally Posted by mmwjr

PS: don't attempt to replace it if the tank is full wait till you get down to 3/4 tank or less to ensure gas doesn't spill out.

How will he know

[Baby Blue]

mechanic tested it. Grounded out the sending unit and the needle on the guage pegged full. That way you know it's the sending unit and not the gauge.
boat is at indoor storage on stands so changing it out before putting it in the water.
thanks for the info.
BB

[mmwjr]

Originally Posted by Phillbo

How will he know

I am assuming he stored it full, therefore he should operate it for a few days to burn off some fuel.

But in your case Phillbo just use a match

[mmwjr]

Originally Posted by Baby Blue

mechanic tested it. Grounded out the sending unit and the needle on the guage pegged full. That way you know it's the sending unit and not the gauge.
boat is at indoor storage on stands so changing it out before putting it in the water.
thanks for the info.
BB

Even when level gas will be right at this point. I recommend running it or drawing some gas out of the tank first

[Baby Blue]

There is approx 1/2 tank of gas. I don't think i explained this well.
mechanic showed that one way to test to see if the problem is the guage or the sending unit, is to ground out the sending unit wire. When you do this the gas gauge will peg full when the sending wire is grounded and thus know that the guage is working and the sending unit is the problem.
thanks for all the replies and info.
BB

[mmwjr]

The sender is basically a rheostat (variable resistor) when low ohms this pegs the gas gauge high, when high resistance the gauge will read low.

[BigJim]

Do you have to remove the tank to replace the sending unit? Can it be replaced when the boat is in the water?

[shrew]

Originally Posted by BigJim

Do you have to remove the tank to replace the sending unit? Can it be replaced when the boat is in the water?

No, the tank doesn't need to be removed. I wouldn't want to do the job with a full tank.