1960 fuel pump conversion

[Cyborg Pirate]

I know this had been gone over I am sure. Hundreds of times. I have seen a great thread on it, but alas I cannot find it. I have seen a few others as well. I have a sierra 18-7350 fuel pump now and I want to convert my 1960 18hp fastwin 15032 over. Anyone know the thread with this topic and pics? Thank you

 

[kfa4303]

Re: 1960 fuel pump conversion

Ahoy Pirate. Sure, here are several links. There are a couple different methods you can use. Do a search here in the forums for similar threads as well.

MIKUNI SINGLE FUEL PUMP from Aircraft Spruce
Converting the Old OMC Dual Fuel
HOW TO CONVERT 50s motors from two line tanks - YouTube

 

[Cyborg Pirate]

Re: 1960 fuel pump conversion

Perfect! The second one was the one I was looking for. Now next question..... Anyone know where I can find a side plate? That way I don't have to drill my existing one? I already checked.... The gasket won't make a good seal on my current side plate if I drill it. Would like to find one already set up for the pump if possible

 

[kbait]

Re: 1960 fuel pump conversion

Tim's outboard most likely has the used bypass cover you need. They'll have the cover gasket too, if needed. 218-682-2331. There are many more salvage yards in top secret file at the top of this forum.
Good luck!

 

[Crosbyman]

Re: 1960 fuel pump conversion

I have done OMC square pumps over a plate and a square Mikuni & nipple with tye wraps
IMHO square pumps on a plate is the best way and you can just cut a cover plate from aluminum stock

drill holes to match the bypass cover screws (use the cover to mark the plate then drill the holes for a perfect fit)
you could remove the bypass cover but it is shaped (sloped) to channel fuel vapors into the chamber So if left it in and drilled a 3/16 hole in the center to get a pulse

drill 3 holes to mount the pump on the plate ( 2 for screws 1 center hole for feeding the vacum pulse to the pump from its rear)

mount the plate/pump so as not to mess up the cowl fit or shifter ...connect your 2 fuel hoses "in & out" and go fishing

I think one member on AOMCI can sell you plates (Frank Robb if my memory is intact) ....but you can make yours in 15 minutes
I did

 

[Cyborg Pirate]

Re: 1960 fuel pump conversion

Wow! Thank you for both responses. I will do some more researching and make a decision. U guys rock!

 

[kfa4303]

Re: 1960 fuel pump conversion

The little square OMC fuel pumps are nice, but kinda pricey when new. Thankfully, they were used on many models so if you look around for a parts motor of similar vintage, you may be able to salvage one. Either way, it will be nice to have a simple, modern, single-line set up.

 

[Cyborg Pirate]

Re: 1960 fuel pump conversion

Yes they are very pricey. I bought a sierra 18-7350 from my buddy at his cost. (He owns a performance boat shop). He ordered it and got it to me yesterday. Haha unfortunately he doesn't do outboards only I/O. I paid 40.00 for the pump. It is supposed to be the replacement pump for the 15033 model. So trying to stay as close to factory as I can in my conversion.

 

[HighTrim]

Re: 1960 fuel pump conversion

I can look but I doubt I have any bypass covers left that will work for you. Making or buying a plate from F_R would be the next easiest idea.

Don't modify the intake manifold as some of the online articles state to do.

 

[Cyborg Pirate]

Re: 1960 fuel pump conversion

That's fantastic! I am waiting to hear back from Tim's outboard if they have one. If not yes please let me know if you do.

Yeah I was not a fan of modifying the manifold

 

[HighTrim]

Re: 1960 fuel pump conversion

Placing a wanted ad at aomci.org in the webvertize section will definitely get you a good affordable cover

 

[Cyborg Pirate]

Re: 1960 fuel pump conversion

Sweet! Thank u

 

[kfa4303]

Re: 1960 fuel pump conversion

check ebay too. a cover plate from any 18/20hp OMC motor of the era will work. The plate may be a different color, but that's no big deal.

 

[Cyborg Pirate]

Re: 1960 fuel pump conversion

Great idea! Had to do some digging. The 1960 calls for a part # of 0307477. I found one for a 1970 fastwin 18hp. But it's part # is 0304817. Are theses covers interchangeable? From all my reading and research the powerhead and parts were the same thru 73. Is this correct? Thank you

 

[HighTrim]

Re: 1960 fuel pump conversion

Different part number as the '70 has the fuel pump, which is what you want.

 

[Cyborg Pirate]

Re: 1960 fuel pump conversion

Cool! I bought it!

 

[64osby]

Re: 1960 fuel pump conversion

Don't modify the intake manifold as some of the online articles state to do.

Just curious why you make this statement. I have done conversions both ways with good results.

 

[HighTrim]

Re: 1960 fuel pump conversion

The reliability is just not there. I am not smart enough to tell you the science behind it, but there is a reason the OMC engineers get their pulse from the bypass cover and not from a modified intake manifold. It can work, and sometimes does, but I have had to redo more than a few of these modifications for guys that couldn't get optimum running out of their motors. Swapping it to the bypass cover remedied this.

Another reason is that it is easier to swap back if need be if the next owner is a purist and doesn't want a single line tank. The components quickly get lost when taken out. Also a pain in the arse to clean the 1 passage that was blocked if a vacuum plug wasn't used, and epoxy was.

 

[64osby]

Re: 1960 fuel pump conversion

I have used the vacuum plug on two and so far all is good. Although having a proper bypass plate is easier, have done two that way.

 

[kfa4303]

Re: 1960 fuel pump conversion

I wonder why the earlier models didn't just come with fuel pump stock? Was it a matter of cost/technology, or a bit of both? Just curious.