Fuel gauge problem

[kengladd]

Hi everyone and happy holidays,

I have an '87 Mako with a 89 gal gas tank. The tank has a magnetic gauge on top but is difficult to get to. I also have a gauge on my dash but it's not accurate. I asked my mechanic if we could just change it but he said that even a new one my do the same thing (because of the ohms?) Has anyone heard of this or have any suggestions.

 

[DJ]

Re: Fuel gauge problem

The guage can only be as accurate as the sender. Your sender is under the magnetic guage, in the tank.

 

[HighTrim]

Re: Fuel gauge problem

You probably have a long narrow tank, thus giving erratic readings on your dash gauge. There are tricks to setting up the arm on the sender to help a little, but if you want exact readings, the best way to go is with a navman unit. You run them inline and they measure how much fuel goes through, thus giving exact readings and update about every 15 seconds. They can also be programmed to do numerous other things. Although, they are not cheap.

 

[kengladd]

Re: Fuel gauge problem

Thanks for the info. I have a question, is the magnetic gauge accurate even if the sender is not? (are they two different systems that measure the gas level differently) Can I rely on it to tell me a true level?

 

[dingbat]

Re: Fuel gauge problem

You probably have a long narrow tank, thus giving erratic readings on your dash gauge. There are tricks to setting up the arm on the sender to help a little, but if you want exact readings, the best way to go is with a navman unit. You run them inline and they measure how much fuel goes through, thus giving exact readings and update about every 15 seconds. They can also be programmed to do numerous other things. Although, they are not cheap.

Take a look at the sensors with in-line floats. I have in-line senders on both of my tanks (1-93 gallons 1- 62 gallons). They don't bounce at all and are very accurate.
http://www.wemausa.com/tank_sensors/details_SSS_SSL_tank_sensors.htm

The Navman units are good as well but be aware that they bottom out at a flow of 1.3 GPH which can be a problem for smaller motors and while trolling with larger ones.

 

[DJ]

Re: Fuel gauge problem

Thanks for the info. I have a question, is the magnetic gauge accurate even if the sender is not? (are they two different systems that measure the gas level differently) Can I rely on it to tell me a true level?

The sender, if I think it is what it is, works both the guage (magnetic) on top of the tank and the dash guage.

High Trim is correct. Long narrow tanks present a challenge to get accurate readings, depending on the fore/aft attitude of the boat. There are some things that can be done but they are sometimes compromises.