Oh no...fuel sending unit?

[krypto69]

So first time out in the new to me 2015 165. Boat has 30 hours, ran fine top speed 54 ish with 3 people.

Problem is gas gauge showed full...Ran for almost 2 hours - gas guage still shows Full. Didn't drop not one single bar. Is this normal? Can't be can it?

Thinking I may have a bad/stuck fuel tank sending unit. I tried to swish it around while looking at the tank when I got home but its too dirty to see any gas moving around inside (or maybe there is no gas to see).

Is it more likely that I have a bad fuel gauge sending unit (if that's what's it called) or the 165 gets really good fuel economy?

Looks like the sending unit might be close to the port side of the tank? So I can replace it myself? Or take it out and fix see if its stuck?

 

[Luc Lafreniere]

I can guarantee you have the design flaw that the float arm is too long. There is no permanent fix unless you're willing to go and bend the float arm. Sorry.

Post in thread 'Ugh, fuel float stuck again. Thoughts on this?'

Jul 6, 2021

Final solution that actually works. Those are mm.

You can see the pencil drawing beneath where things were located before the bends. Accuracy is almost identical. The only downside to this is that the tank remains full a little longer than before. Fuel level has to be 27.5mm lower.

• Luc Lafreniere

• 

 

[krypto69]

ahh thanks Luc - I see your post now. Glad you posted a solution. Thanks again.

Sooo...glad I went back to the dock when I noticed I had used no fuel in two hours..lol.

Questions tho.

So I need to take it apart as you describe and add a bend, the float is straight to start with. This makes it a bit shorter. Correct so far?
In the pics there are two different bends tho one is 27.3 next pic is 34.5. Which one do I use?

Ordered a digital caliper - cool.

 

[Luc Lafreniere]

yeah, sorry, dinner was being served and I didn't get to post my follw up lol. It's missing one of the measurements. Someone did this recently and ended up with two bends of 34.5mm each. Apparently that worked. So I'd go with that.

The arm isn't straight... there's a bend at the bottom already. Look at post #1 on that other link and you'll see what it looked like originally. You're going to be adding two bends. One to the right and then one to the left. This will end up shortening the arm by a bit and solve this problem forever.

It also doesn't need to be that precise. But digital calipers are a great tool to have anyways.

Yeah, you and many others on the older models have had this issue. Many boaters have ran out of gas because of this. It's odd, Scarab has never owned up to it. I've received every excuse in the book. The fact is, the arm is too long for that tank design. The good news is, it's free to fix if youˋre mechanically inclined.

Post #8 on that page also has the description of what you need to do. Make sure to read that. I do recommend doing this when you have less than half a tank (use your judgement since you have no gauge working). Also, turn off the master red switch and disconnect the battery before playing around in fuel.

 

[krypto69]

ah okay, Yep I read #8 a few times. Hoping I can get the big nut off (that's what she..) anyway I'll try your suggestion with a screwdriver and hammer.

I guess the part I don't understand is this..I misspoke I meant the upper part of the arm is straight so I will put one bend in it like you show here:



And that's the only bend correct?


If so, so why is there is there a new different bend in the same place?

 

[Luc Lafreniere]

That is a good question! lol It's been a while. I think at the time I was trying to "show my work" to show how I got to 34.5mm. So ignore the 27.3mm. The other person made both sections 34.5mm. See this other photo that shows the other section.

 

[Luc Lafreniere]

I'll update my post when I have a chance. Avoid all of this confusion. It just keeps coming up......

 

[krypto69]

Great, I'll go with 34.5.

Yeah knowing that measurement (Dist?) would be helpful, important but I think I can get it pretty close based on other dimensions.

REALLY appreciate all the help Luc. Good karma to you!

 

[krypto69]

using 'imagemeter' the unknown value of 'Dist?' is approx 48 mm.

 

[krypto69]

 

[krypto69]

did the mod - wasn't easy or fun. But your instructions were great - thanks again.

Haven't tested but don't want to do it again. Will update after I test.