Not sure I understand this...

[Chemdawg]

I have been thinking about something lately, and I want to know what other people think.

My boat is a 1987 Arrow Glass Carisma 175. IT has the 3.0L Mercruiser with Alpha One outdrive. When the boat was new, it had the mechanical fuel pump with filter built in, and was plumbed with solid pipe from the pump to the carb. Now I'm not sure what was from the tank to the pump. There is an anti-siphon fitting coming off the tank, and there was fuel line from that to the fuel pump. IS this correct?

I hear all the time that there is supposed to be a fuel filter, then fuel water separator, then the fuel pump. But this was not the case when I got it. It's easy enough to make it that way since I have the fuel water separator in there now. But I'm using an electric pump. I'm going back to the mechanical, since I'm having too many issues with the electric.

So what is correct for the plumbing from the tank to the pump?

 

[Bt Doctur]

from the tank there is the anti-syphon mounted at the tank. looks just like a barbed fitting. From there rubber fuel line to the "in" of the fuel/water sep,
the "out" of the fuel sep goes to the fuel pump inlet, the out of the fuel pump goes to the carb

 

[Chemdawg]

Got it. I have the fuel water sep. So that's not a problem. I'll relocate it, then run it the correct way. The guy I bought the boat from may have removed it at some point. Thanks.

 

[Scott Danforth]

fuel/water separators were optional on the 3.0's Like Bt Doc said, Tank, anti-siphon, marine rated line, fuel pump, (optional Fuel/Water filter), Carb.

 

[Starcraft5834]

I have the same engine, same year,, installed a water/fuel sep filter this year....runs better.......

 

[Fun Times]

An inline fuel filter between the tank and water separator filter is an option on some models and standard on others. You're 3.0l most likely had neither when new.

It's your choice to add one or not but since you already have a water separating filter and going back to a mechanical pump, it might be better not to add one as it may interrupt with flow volume.

 

[thumpar]

Make sure the line from the pump to the carb is solid or the A1 type tubing.

 

[Starcraft5834]

An inline fuel filter between the tank and water separator filter is an option on some models and standard on others. You're 3.0l most likely had neither when new.

It's your choice to add one or not but since you already have a water separating filter and going back to a mechanical pump, it might be better not to add one as it may interrupt with flow volume.

for what it's worth.. I have a mechanical fuel pump, added separator, did install new fuel lines too.. runs very well....

 

[Bondo]

I have been thinking about something lately, and I want to know what other people think.

My boat is a 1987 Arrow Glass Carisma 175. IT has the 3.0L Mercruiser with Alpha One outdrive. When the boat was new, it had the mechanical fuel pump with filter built in, and was plumbed with solid pipe from the pump to the carb. Now I'm not sure what was from the tank to the pump. There is an anti-siphon fitting coming off the tank, and there was fuel line from that to the fuel pump. IS this correct?

I hear all the time that there is supposed to be a fuel filter, then fuel water separator, then the fuel pump. But this was not the case when I got it. It's easy enough to make it that way since I have the fuel water separator in there now. But I'm using an electric pump. I'm going back to the mechanical, since I'm having too many issues with the electric.

So what is correct for the plumbing from the tank to the pump?

Ayuh,...... I yer quote, the fuel filter, then fuel water separator, are 1 'n the same unit,.... What sorta problems ya havin' with the fuel pump,..?? What sorta Tests have ya done, to narrow it down to the fuel pump,..??

 

[Chemdawg]

When I bought the boat, the fuel pump was shot. Instead of spending the money on a new mechanical, I used a Holley blue pump and regulator, and wired in an oil pressure safety switch. The problem is that the regulator I'm using is a dead head style, and I need a return style. Too much work to pull it all apart now. So I'm going to just go back to the mechanical fuel pump. So I have one on order from right here at the boats store, and when it comes, I will eliminate all the electric fuel pump stuff.

 

[Bondo]

When I bought the boat, the fuel pump was shot. Instead of spending the money on a new mechanical, I used a Holley blue pump and regulator, and wired in an oil pressure safety switch. The problem is that the regulator I'm using is a dead head style, and I need a return style. Too much work to pull it all apart now. So I'm going to just go back to the mechanical fuel pump. So I have one on order from right here at the boats store, and when it comes, I will eliminate all the electric fuel pump stuff.

Ayuh,... Gotcha,... Just as a recap, from yer tank, with good marine fuel hose, to the W/S Filter, to yer fuel pump, then to the carb,...
Put yer filter housin' where ya can get at it reasonably Easy,...
It's a Great diagnostic tool, 'n an Easily changed filter, get's changed,...