Fuel Pump Rebuild Question..

[*WEAVER*]

HI Guys, I have a 1990 Mercury 90 horse 3 cylinder outboard, the fuel pump rebuild kit # is 42909A4

I have a few questions that I hope you can help me with.

my fuel pump had the black check valve discs installed along with the clear check valves. Now this rebuild kit I got just has the clear valves in it, and the instructions has no mentions of the black check valve discs, does those need to go back in it? Or do I just use the clear discs and that is all?

My other question is, it tells me I need to enlarge the check valve holes to .125 in diameter, and hole edges chamfered so that these new nylon retainers can fit, what exactly does chamfering the hole edges mean? does that mean just clean them up?

I would appreciate any help on this, as I am trying to get this finished. Thanks

 

[Barnacle_Bill]

Re: Fuel Pump Rebuild Question..

Just use the clear check valves that come with the kit. The last 2 that I did did not need any modifications. And yes, they mean to clean the sharp edges off.

 

[*WEAVER*]

Re: Fuel Pump Rebuild Question..

Bill, thanks for the help. Do you know why they used the black check valve and the clear plastic check valve, and now you just use the clear plastic one by itself? Thanks

 

[Barnacle_Bill]

Re: Fuel Pump Rebuild Question..

Bill, thanks for the help. Do you know why they used the black check valve and the clear plastic check valve, and now you just use the clear plastic one by itself? Thanks

Have no idea. The ones I did didn't have both in them, just the old rubber type. E-10 causes the edges to curl up and they don't seal properly. That is why they changed them to the plastic ones.

 

[j_martin]

Re: Fuel Pump Rebuild Question..

The black check valves are the old ones. They get like bacon in ethanol. The new ones are clear plastic and are not affected by the ethanol. If both were in there, whoever did it last had no clue.

The easiest way to chamfer a hole is to spin a larger drill bit against it with your fingers.

hope it helps
John