1970 mercury 650 fuel pump 1 or 2 ?

[chrismercury]

Does anyone know if a 1970 mercury 650 4 cyl<br />outboard needs 1 or 2 fuel pumps? I bought this motor with only an upper fuel pump, it runs to the upper carb then from there to the lower carb<br />is this how it's suposed to be. Or do I have to put the lower fuel pump on, and run it to the lower carb??? <br /><br /> thanks for any help

 

[mellowyellow]

Re: 1970 mercury 650 fuel pump 1 or 2 ?

welcome aboard,<br />pretty sure they came from merc with 2 pumps.<br />can tell you my inline 6cyl '70 1150 has 3.<br />mounted on right side of block from behind.<br />have heard of folks adding an extra electric<br />pump to them... the factory pump works off of<br />internal pressure. maybe this is what yur seeing?<br />good luck,<br />M.Y.

 

[chrismercury]

Re: 1970 mercury 650 fuel pump 1 or 2 ?

thanks for the info

 

[mellowyellow]

Re: 1970 mercury 650 fuel pump 1 or 2 ?

you'd be surprised how many of these old girls are<br />still running... click on "search" link above and<br />there's hours of reading about them on specific<br />questions. if'n you don't already have a service<br />manual, get one! they are great motors but they<br />require good maint. there's a link below for<br />manuals, or at local library for free perhaps?<br />thirsty motors, so start with fuel starvation.<br />good luck!<br />M.Y.

 

[Gold Bear]

Re: 1970 mercury 650 fuel pump 1 or 2 ?

chrismercury<br /><br />Not trying to start any trouble here... I used to have a 1972 50 horse and I'm sure it had only one fuel pump.<br /><br />Also, my 1971 115 horse has two fuel pumps. There is a "boss" on the side of the block for a third, but it has only two pumps.<br /><br />Are you having any problems with the way the eingine is running?<br /><br />Good Luck,<br /><br />Gold Bear

 

[chrismercury]

Re: 1970 mercury 650 fuel pump 1 or 2 ?

I only heard it run for a second when I bought it. I tried to start it but it just turned but wouldn't start or even try to.not sure what a "boss" is, but there is a place under the upper fuel pump that looks like you could put a fuel pump just like the upper one.

 

[Gold Bear]

Re: 1970 mercury 650 fuel pump 1 or 2 ?

chrismercury <br /><br />That is a "boss". I believe my old 50 horse was the same way - one fuel pump and an extra "boss".<br /><br />If you find she is not getting fuel, it is simple to change the fuel pump diaphram.<br /><br />Check for fuel, spark, timing, and compression. You may have to re-build the carbs etc.<br /><br />Do a search for trouble shooting on this board and I'm sure you can get the old girl running.<br /><br />Good Luck,<br /><br />Gold Bear

 

[chrismercury]

Re: 1970 mercury 650 fuel pump 1 or 2 ?

Thanks, I already bought a kit to rebuild the fuel pump,I'll get the carb kits and do it all at the same time.<br /><br />Thanks for the help