1987 70HP fuel line ID

[skipper123]

On a 1987 70HP 3cyl merc their is a small fuel line on the starboard side of the engine that runs from the bottom carb up to a nipple right at the top of the block. Im not even sure its a fuel line but a couple weeks ago I noticed fuel dripping from it at the bottom where it had fallen off the carb. Can we disconnect this line and plug the nipples ? This hose is very small like 1/8 " Its not the fuel line feeding the engine which is on the port side of engine.

 

[aussieflash]

Re: 1987 70HP fuel line ID

No you cant plug it up.That line is your bleed line.Its there to recirculate unburnt fuel.Available at most parts outlets.

 

[aussieflash]

Re: 1987 70HP fuel line ID

This is what you need.
32-892024122 | TUBING-20 FEET | Mercury | Crowley Marine.

 

[skipper123]

Re: 1987 70HP fuel line ID

Thanks for the reply and yes that makes since. Glad I did not cap it.

 

[Maxz695]

Re: 1987 70HP fuel line ID

It also sends oil to the end cap seals to keep them lubed

 

[ajgraz]

Re: 1987 70HP fuel line ID

As has been said, the unburnt oil and gas drippings inside the block pool at the bottom of the crankcase, then exit through that one-way nipple via crankcase pulsations, then up to the top through that hose where some will eventually wind up going into a cylinder and getting burned.

Interesting fact: prior to about 1980 or so, that little hose was also T'd off to to the front cowling support, where by design unburnt petro ran down the outside of the leg and straight into the water.

 

[Maxz695]

Re: 1987 70HP fuel line ID

Good one Ajgraz. I made sure whaen i did my rebuild that the clogged ports where clear and the check valves where working. So it forces the extra oil out of the lower and then into the intake on mine and there is an upper fitting as well to the top endcap on mine.