What is this tube for???

breeder44

Cadet
Joined
Oct 4, 2007
Messages
10
Hi, I just purchased a 1999 Bayliner with the 3.0L Merc and there is a yellow hose running from the bottom of the motor to the top but is not connected to anything. Does anyone know what that would be for or where it would go to??
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
Re: What is this tube for???

safety- in case the fuel pump diaphragm ruptures, instead of dumping fuel into the bilge, it dumps it into the carb through that hose... making the engine run rich and/or stalling it

there's a nipple on the carb that should be attached to - just slips on - but you can use a wee tiewrap if you want to help hold it

that section of hose on the fuel line with the 2 clamps doesn't look right to me... might want to check a parts book online somewhere - I think that should be steel line 1 piece from pump to carb.... I wouldn't trust hose clamped onto unbarbed fuel line.
keep that one in your tool box and tee a gauge into it for troubleshooting fuel supply issues down the road
 
Joined
Aug 18, 2011
Messages
6
Re: What is this tube for???

There are numerous things wrong with that photo.
1. That rubber hose section is against USCG regulation. Any fuel lines (inside the boat) where fuel is "pushed" instead of "sucked" from here-to-there has to be steel)
2. Is it just me... or does that carb inlet fitting face the wrong direction? To port?!? That would explain the rubber hose: The original metal fuel line doesn't reach.
3. Why is that carb float body silver?
4. There's probably no nipple for that yellow hose which is why it's hanging in the breeze.

It almost looks like someone tried to redneck an automotive / incorrect carb on that engine. Might wanna browse your year / make / 3.0L on eBay just for photographic comparison.
 
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