Fuel Float - Boy do I feel dumb...

[IDoSeaDoo]

I've had trouble with my fuel gauge since I bought my boat. It always read empty, regardless of the amt. of actual fuel in tank. My first suspicion was the sending unit. I pulled it out and checked the float. It seemed fine, magnets solid in place. I wired up another gauge (off a PWC) and checked sending unit operation: worked perfectly. Float up=full, down=empty. Great, the problem was my gauge... or so I thought. Bought another gauge, installed it and same thing: reads empty. I was furious, esp. since I destroyed my previous (probably 100% perfect) fuel gauge in attempts to learn how to fix it. Well, I didn't find any obvious things wrong with it, but now it's in pieces. My next order of bussiness was to check the resistance values coming from the sending unit. The test showed 90 ohms, which correlates perfectly with EMPTY. Well damn, if the float worked out of the tank and now is working saying it's EMPTY, it must be because my float stopped floating . I think the material of the float is actually saturated with fuel, and is sinking. Now I know I should just buy the $20 replacement unit, but that would take a week to get here. I'm going out tomorrow and decided to conduct an experiment: I drilled a .5" hole in it and stuffed an equally sized cork cylinder inside. I glued the ends with black RTV. I hope that's enough cork to float this sucker. I'll let you guys know if it works Wish me luck!

 

[Dr Honda]

First.... We say all the time about the floats sinking. It's a known problem. The new float is blow molded, and not a foam chunk.

Second... The RTV isn't fuel proof. It's fuel resistant... and if it's submerged... it will decay. BUT... I'm sure it will be fine for a temp fix, as long as you let it cure for 24hr's before putting it back into the tank.


Anyway... the issue is our newer fuels. The foam on the original float doesn't like alcohol, and it will absorb it.

 

[IDoSeaDoo]

Do you think the cork cylinder would float it? Does cork absorb alcohol? Maybe I should just rip the RTV back off and leave the cork in. The only reason I put that stuff on there was in hopes of trapping some air bubbles. But yea, I could totally see RTV degrading in the fuel over time.

 

[Dr Honda]

Yes... if it's natural cork... it should work. BUT... cork is basically soft wood... so you can't leave it in there forever. A few weeks, until your plastic one shows up will be fine. Honestly... I would worry about the RTV over the cork. If you haven't glued it together yet... you can use a product called seals-all. It's a little more fuel proof. I use it to glue caps closed on fuel tanks that I use in my RC Jets. It's in a red and yellow tube, and you can get it at Home Depot or Lowes.

 

[Coastiejoe]

I agree, get the replacement as the cork will break down and you will get residue and chunks in your tank...

 

[IDoSeaDoo]

Yea, I was going to get the replacement anyway. The cork didn't work anyway. Those 4 magnets are heavy...