I'm converting my 1957 Evinrude 18hp from the 2 line pressure tank to the single line as I have a myriad of the single line tanks kicking around that are in great shape, and the pressure tank that came with it has rusty innards.
I used the instructions found for the 5.5hp, using a vacuum cap to block off one crankcase port behind the intake manifold, and using that as a source for vacuum. I picked up a rectangular pump very similar to the Mikuni that seems to be the choice of everyone's conversion.
I had a couple questions. I was going to replace the glass bowl with an inline filter. However, I haven't gotten around to it, and for the sake of getting it running with what parts I have, I'm just going to use the bowl. Now, should i hook the pump up before the bowl, or after the bowl? Meaning, line from connector on outboard goes to bowl first or pump first? For obvious reasons it would make more sense to go with bowl first, as it will keep some stuff out of the pump (it has a filtering stone or something in it)
My 2nd question/issue is it seems that the pump isn't doing anything to speak of. I primed it up, and looked for leaks and heard the fuel going in to the carb bowl (had my ear to it) and it shut off and the bulb got hard like it should, however after several attempts at starting it, the bowl was dry. I know the theory of how vacuum fuel pumps work but have no idea how to actually see if it is..
3rd and final question/issue: Will the small pump supply enough fuel to feed the 18? I know it works on the smaller ones, but I'm concerned that maybe it won't supply enough volume, and I might be better off trying to locate a bypass cover and using a standard pump. Obviously, this would be very easy to do, but I've got a pile of vacuum pumps from the plastic circular briggs replacements to the Mikuni retangular one. What do you think?
I used the instructions found for the 5.5hp, using a vacuum cap to block off one crankcase port behind the intake manifold, and using that as a source for vacuum. I picked up a rectangular pump very similar to the Mikuni that seems to be the choice of everyone's conversion.
I had a couple questions. I was going to replace the glass bowl with an inline filter. However, I haven't gotten around to it, and for the sake of getting it running with what parts I have, I'm just going to use the bowl. Now, should i hook the pump up before the bowl, or after the bowl? Meaning, line from connector on outboard goes to bowl first or pump first? For obvious reasons it would make more sense to go with bowl first, as it will keep some stuff out of the pump (it has a filtering stone or something in it)
My 2nd question/issue is it seems that the pump isn't doing anything to speak of. I primed it up, and looked for leaks and heard the fuel going in to the carb bowl (had my ear to it) and it shut off and the bulb got hard like it should, however after several attempts at starting it, the bowl was dry. I know the theory of how vacuum fuel pumps work but have no idea how to actually see if it is..
3rd and final question/issue: Will the small pump supply enough fuel to feed the 18? I know it works on the smaller ones, but I'm concerned that maybe it won't supply enough volume, and I might be better off trying to locate a bypass cover and using a standard pump. Obviously, this would be very easy to do, but I've got a pile of vacuum pumps from the plastic circular briggs replacements to the Mikuni retangular one. What do you think?