Which carb on the top?

[PensacolaJason]

I took my carbs off to teach myself how to rebuild and clean them and took a bunch of pictures so I'd remember how they went on and were setup. One picture that I didn't take was to figure out which bowl went with which carb. In the screenshot I've attached, you'll see that one of the bowls has a fuel input (circled) and I can't remember if that bowl with the input needs to be on the top or bottom carb or if it even matters. Does anyone know?

I left the linkages attached the the carb that was originally on top (left).

 

[Tim Frank]

Re: Which carb on the top?

It will depend a lot on what your motor is....presumably it is an OMC....

 

[PensacolaJason]

Re: Which carb on the top?

It's a 1983 50hp Johnson. J50BELCTA

 

[old sparky]

Re: Which carb on the top?

i just bought a 65 evinrude, the carb. with that fitting was on top. there was a short hose attached to it and it was plugged with a bolt, not being used. not helping you much, but, i'd like to know what it was used for to begin with. my motor has 3 carbs, does not run and i'm trying to figure out why. i need gaskets and not sure which to buy.

 

[phipps]

Re: Which carb on the top?

It's a 1983 50hp Johnson. J50BELCTA

I have a 1983 Evinrude 50HP and neither of my carbs have that fitting. Both of my carbs look identical other than the linkage connections.

 

[phipps]

Re: Which carb on the top?

I just looked up your carbs on the parts diagram at shop.evinrude.com and that fitting is not shown on the parts diagram.

If you blow air through it does it come out anywhere?

 

[Tim Frank]

Re: Which carb on the top?

1) Did you buy the motor new....or was it used? (i.e. are you 100% certain that those are the original carbs?)
2) Are you rebuilding the carbs just because....or is there a performance issue that you are trying to address?
3) If there is a performance issue, has it just started or if not, how long has it been a problem?
4) If yes to 3) if you bought the motor used, how long have you had it and has it ever run properly for you?

 

[PensacolaJason]

Re: Which carb on the top?

After studying my photos I found a mark on the float bowl attached to the top carb so I used it to figure out where it needed to be. It went with the top carb. After taking them back out to install on the motor this confirmed it because the bottom carb sits so close to the bottom that it wouldn't have been able to fit.

That fitting is what connects the hose from the fuel pump to the carb.

 

[PensacolaJason]

Re: Which carb on the top?

I just looked up your carbs on the parts diagram at shop.evinrude.com and that fitting is not shown on the parts diagram.

If you blow air through it does it come out anywhere?

This rough diagram of my setup might help. That fitting (in red) is the fuel feed coming from the fuel pump. The fuel flows into the top carb, fills up and then fills the bottom carb via the connecting hose.

 

[PensacolaJason]

Re: Which carb on the top?

I just looked up your carbs on the parts diagram at shop.evinrude.com and that fitting is not shown on the parts diagram.

If you blow air through it does it come out anywhere?

Strange, I noticed that too on the parts diagram. I wonder how the fuel gets to the carbs without that fitting?

 

[phipps]

Re: Which carb on the top?

My line from the fuel pump tees and there is an individual line running to the small nipple on the side of each carb.

 

[phipps]

Re: Which carb on the top?

This rough diagram of my setup might help. That fitting (in red) is the fuel feed coming from the fuel pump. The fuel flows into the top carb, fills up and then fills the bottom carb via the connecting hose.

View attachment 209142

Does the fuel flow to the bottom carb get stopped when the float closes the top carb?

 

[PensacolaJason]

Re: Which carb on the top?

Does the fuel flow to the bottom carb get stopped when the float closes the top carb?

This motor is new to me, but it looks like the fuel flows through the top carb and down to the bottom carb which fills up and then moves up to the top carb and once they are both filled the bubble becomes hard.

The last motor I had was a small 15hp with only one carb so this setup is new to me.