Mercruiser 165 inline 6 Help with New Carter Fuel Pump

[corona2627]

Been working on my 71 Glastron with a Mercruiser 165 inline 6. Have purchased a new carter fuel pump. The old pump was totally different, no filter, and no vent to carb. I am assuming this fuel pump has a vent to carb due to the fact that there in a IN port and a OUT port plus and brass barb which I think, from researching, that this is a vent to carb. Where does the vent tube connect on the carb? what type of tubing do you use and what size? There is a vent now on the Rochester Carb that connects to the valve cover, would I connect there and with what type of connector?

Please help...

Thanks,

Dianne

 

[cr2k]

Re: Mercruiser 165 inline 6 Help with New Carter Fuel Pump

Clear vinyl tubing is good. The vent usually goes to a similar barb usually found on the air horn of the carb right below where the flame arrestor sets. It does not go to any vacumme source it will just flow into the throat of the carb.

 

[corona2627]

Re: Mercruiser 165 inline 6 Help with New Carter Fuel Pump

Thank you...So instead of clear vinyl, would fuel line do as well? What about the heat? Would that damage the vinyl vent tube?

 

[ziggy]

Re: Mercruiser 165 inline 6 Help with New Carter Fuel Pump

while i've not done the mod your doing, i believe i understand what needs to happen for it to occur. fwiw, the next time my fuel pump fails, i'll be doing the mod too.

i think the idea of the clear fuel line is so ya can see the fuel being dumped from the fuel pump indicating a ruptured diaphragm in the fuel pump. i understand ya can get some of this clear fuel line from a lawn mower type shop. don't know that for a fact, just read it.

i believe yer on the right track for where to connect the clear tube too on the carb. the barb on the carb. screws into the carb so if the dia. needs changing, i would think a trip to the hardware store will get you the proper dia. brass barb. same size as the fuel pump barb dia.

the other obstical would be the crank case vent that went from the valve cover to the carb. i had a 72 165 and a 75 165. there was a change in valve covers for the crank case vent. you know the old style. here's the newer style.

pic is of the 75. the fa has a mod for the breather tube + the valve cover has a mod for a crank case vent plug. similar to a pvc valve, but w/o the valve, it's just plain open. a place to connect the hose.

imho, heat won't be a problem. there shouldn't be much heat anyways. feel your manifold when warm to prove the point. ya can set yer hand on it when it's as hot as it's gonna get.

 

[corona2627]

Re: Mercruiser 165 inline 6 Help with New Carter Fuel Pump

Thank you for all the great help, I will see if I can understand better when I am in front of the carb. I will also try to find some of that clear tubing. You all are so great, thanks again.

 

[Fishermark]

Re: Mercruiser 165 inline 6 Help with New Carter Fuel Pump

Here's a post where I asked some similar questions a few years ago. Some good discussion and information.

Old post with similar questions
Here's what I finally did with mine: