Fuel Pump Numbers

[FillupD]

I bought a fuel pump Sierra 18-7353 about a year ago to go on a 1973 50hp 50373r motor. I finally got around to put it on but it is slightly different. It does not bolt on to block at the top hole (which seems to be OK). The fitting that goes to the carbs is smaller than the old one also. I can get a bigger fitting if this pump will work.

I have read a lot of posts on here and it looks like it replaced a few VRO setups and worked OK. I'm a little undecided because I see different numbers for these pumps, some with 2 outlets and with 3. This one has 3 and so does a #438559.

Yet, the sierra number does not cross over, nor is my particular motor listed for the 18-7353 or a 433386 but they the 433386 looks the same.
I really don't want to buy another one, or really wait to get this motor running so I thought about getting a little bigger fitting for the fuel to carb and trying it out. I hate to use a brand new pump if it is not going to work though.
What do you think?
My choice is buy a 438559 or a 433386 with the correct fitting, (looks like it anyway), OR change the fitting in the one I have 7353 and install it.

I might add, I have a new 18-7820 rebuild kit, but I think I lost the spring that goes onto the center plunger the fuel cap screws onto. I pretty sure there was a spring in there a year ago?

 

[tx1961whaler]

Re: Fuel Pump Numbers

I just read through a ton of old posts, and I never found a definitive answer.
I would think that a 18-7350 would provide plenty of fuel for a 1973 50 HP. If it were my motor, I would try it to see how it works, especially if I already owned the pump. But it's your motor......if you put it on there and it cuts out at WOT, then you know it isn't up to the task.

 

[FillupD]

Re: Fuel Pump Numbers

I have tried several stores to find a fitting and to no avail. I'm going to have to MacGyver something up to see if it will even work I guess.
If I had a spring for the plunger, I could rebuild the old one I have and get things going but that is hard to find also.
Anyone have an old fuel pump laying around that may have a spring you are not going to use? I'll pay for the spring and shipping if you would want to part with it.

 

[FillupD]

Re: Fuel Pump Numbers

I have stumbled on to an old fuel pump that is intact complete with spring. I have a rebuild kit, so if everything works out OK, I'll have a running motor tomorrow.
Thanks for the reply "tx1961whaler".

 

[tashasdaddy]

Re: Fuel Pump Numbers

187353 is for 20-30 hp motors, remember if it is suppling fuel for just 20 -30 hp, it is only delivering oil for those engines.

i have replaced many pumps in my business, i would not risk my reputation using the wrong pump. i have also found, that rebuilding is not profitable, due to possible problems later.

replace with the proper pump, 438559, and be done with it. know you have a dependable pump.

 

[FillupD]

Re: Fuel Pump Numbers

Thanks, Sounds like good advice. I took the old one apart and it looked OK but I must have removed it for some reason and never got around to rebuilding it, so your experienced opinion is appreciated. There isn't much to them so it would be hard to see where a problem could lie.

I can at least return my kit and be 17 bucks ahead of the game from the start. I got it from NAPA this weekend. I guess it is it is only one day more. iboats warehouse must be close to Lincoln. Orders are here most of the time the next day, that is a nice benefit.