Mercury Fuel Pump question.. - The Hull Truth

WEAVER · 10-20-2009, 09:22 PM

I have a 1990 mercury 90 horse 3 cylinder, and I was having problems with the engine not starting, and surging in idle etc, come to find out, I took the fuel pump apart tonight, and the front diaphragm was ripped, from what I read, this is what is causing my problem. Thankfully I found that out, it was driving me crazy trying to figure out what the problem was.

My question is, I need to order the stuff to repair this fuel pump, and I am not for sure what to get. Is there a fuel pump rebuild kit, or do they sell everything seperate or what exactly would I need? And where online could I get something like this, I've never really purchased outboard stuff online before. Thanks for your help.

TakeItEasy · 10-20-2009, 10:22 PM

Need engine serial # and usboatsupply and check the diagram , about $90 range for assembly I think you want.

http://www.usboatsupply.com/Mercury_...ms=5890&si=682

mattmuttsmithx · 10-20-2009, 11:45 PM

The part number you need is 21-857005a1 and you will need one of these kits for each fuel pump (three kits if you have three fuel pumps/one kit if you have one fuel pump). This kit will run you about 10-15 bucks. That is the mercury marine part number. Every Mercury Marine dealer should have about 12 of them. They are the same on all of their engines that use that design. The kit will have all your springs, diaphragms, pins, and etc. It will NOT come with the fuel pump body. If you need the actually body of the fuel pump then just go ahead and buy a new fuel pump because it will all ready be put together and they are pretty reasonable. The Mercury Marine part number of the complete fuel pump is 14360a78 and will run you about $95 depending on where you get it from.

The items that are in the kit are not available from Mercury Marine separate for the most part. So everything will be superseded to the fuel pump kit.

If you call your local parts house up and they do not have the part number for the kit see if they have the fuel pump. It might save you some time just to get the whole fuel pump instead of driving 100 miles for a kit.

Good Luck. If you have any questions fill free to PM me. I have extensive knowledge about this.