HELP--Mariner 115 Fuel Pump Rebuild Question

[jp2570]

I tried searching, but could not find a direct answer.

I am installing a Sierra Fuel Pump Kit 18-7817. Does anyone know where I can find instructions for this kit? i have two sets of check valve disks which I assume the clear goes over the black. At least that is the way the old ones were installed. However, the new kit does not have rubber pins, it has white plastic pins. Which way are the installed. The pin is white plastic with a longer straight pin on one end. Does the split end insert through the disks and then the longer end face opposite? I ask because it looks like it is too long and not very secure. I know it is a dumb question, but it is my first experience with this pump.

 

[Chris1956]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

OK, That kit looks to fit the older and newer fuel pumps. Which fuel pump do you have? The square one or the one that looks like a figure 8? The figure 8 one (older) has a clamp that holds the check valves, which do not look to be part of your kit. The white chack valves are for the square fuel pump. There is a particular was to instll those and the pins get broken off and then reinstalled to hold the check valves. A service manual (even a Selloc) will explain it all.

 

[jp2570]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

I have the square pump. The pin part looks too long, but the manual that I have, which I bought online and downloaded last year does not mention the pins, or at least the search I performed did not turn it up. I too thought the pin portion make be broken off, but I was afraid it would leave a hole in the center, so I installed them as is. I tested the boat yesterday and it performed wonderfully. I looks like Sierra would include instructions, especially when the parts are redisigned.

 

[jp2570]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

Adam from Sierra sent me the attached PDF, but it does not have a nararative on what to do with the pin. What is your take on it?

 

[Chris1956]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

JP, I cannot see the attachment. I only rebuilt one of those pumps a couple of years ago. If my (failing) memory is accurate. You were suposed to install the one way valves, break off the pins, and then insert the pins into the holes. I did it some other way and it worked fine. I think I just installed the valves and pushed the pins flush.....

 

[jp2570]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

Thanks Chris. I finally bought a Mercury Marine Quicksilver kit. It had instructions in it. You have to drill the pump body retainer holes to 1/8 inch to accept the new plastic pins if your body had the rubber pins, which mine did. After that you break the pins off and insert them flush. Also, the Quicksilver kit only has the parts you need, like the clear disks----no rubber. So problem solved.

Sadly, Sierra tech had no idea this had to be done. I emailed them and they tried to help but did not know---even after reviewing their shop manual.

Thanks.

 

[Dave1027]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

Hey JP,

I'm doing the same job on my 100 hp with the square body. I also could not get the plastic pins to fit so a use slighting smaller nails. Seems to work fine.

What do you mean no rubber? My pump originally has plastic disks with rubber disks. Are you saying we are not supposed to use the rubber disks for this pump?

On more question about the Sierra kit. According to my book and also looking at the old diaphrams, one of the diaphrams has two holes in it. The book says the holes allow the oil injection to work. My Sierra kit diaphram does not have holes. Should I cut holes in it?

Dave

 

[jp2570]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

The quicksilver kit did not have any rubber disks in it at all, just the clear plastic ones. Also, both diaphrams were solid. With my pump design, the pump would not function if either diaphram had holes in it. The oil and gas on my motor are mixed at the autoblend unit and the diaphram/pump has nothing to do with the oil injection. If you have a different oil injection system, your's might be different. Note, my pump had both the plastic and rubber valves installed when I fisrt took it apart. The new oem kit only has the clear. I have read on here that the rubber disks are not needef due to ethanol problems.

 

[Dave1027]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

That's odd. My Merc manual says the auto injection won't work without the holes. I went ahead and cut holes in the diaphram just like the original with a paper hole punch. I have a 1988 Merc. Maybe that's why. What year is your 115?

I would think the rubber disks would seal better plus the original had rubber for 22 years and no ethanol damage that I can see.

 

[jp2570]

Re: HELP--Mariner 115 Fuel Pump Rebuild Question

That's odd. My Merc manual says the auto injection won't work without the holes. I went ahead and cut holes in the diaphram just like the original with a paper hole punch. I have a 1988 Merc. Maybe that's why. What year is your 115?

I would think the rubber disks would seal better plus the original had rubber for 22 years and no ethanol damage that I can see.

Mine is a 1987 Mariner inline 6. Does yours have the oil tank on the engine or a tank in the fuel tank compartment where it premixes before the fuel pump? Mine had the rubber and plastic disks installed when I first took it apart, but the new kit that I purchased only had the clear plastic ones. I looked at a schematic for the 1988 mercury/Mariner100 HP motor and what I saw is an entirely different setup than mine. That probably explains the differences. By the way, the rubber disks in mine looked OK too, but I replaced them while I had the pump apart with the new ones in the kit.