Maintaining mechanical fuel pump

[Wet Wonder]

I'm going through the fuel system from the pump backwards to the tank, checking for leaks, checking fittings, vacuum from the pump, etc. The manual suggests, during fuel system maintenance, to take the mechanical fuel pump apart to inspect and clean, and to replace failing parts as needed.

Is disassembling the mech fuel pump something that folks tackle? Or do folks prefer to just swap out the entire pump if they have suspicions about it?

 

[bustermin]

Re: Maintaining mechanical fuel pump

Is disassembling the mech fuel pump something that folks tackle? Or do folks prefer to just swap out the entire pump if they have suspicions about it?

Id say that depends on cost, if it is an inexpensive pump, why not just change it.

 

[Wet Wonder]

Re: Maintaining mechanical fuel pump

A new or remanufactured pump is between $100 and $150. I suppose that taking the old one apart, cleaning it, and replacing any wearable parts would probably cost a few dollars at most, if done right.

 

[WizeOne]

Re: Maintaining mechanical fuel pump

Are all fuel pumps created equal? Do all motor outdrive combinations use the same fuel pump? Do any marine fuel pump manufacturerers make rebuild kits available?

 

[windsors03cobra]

Re: Maintaining mechanical fuel pump

I'm buying a spare pump to carry with and the necessary stuff to make it work along with the tools. Currently running on a 33 year old unit and it worries me every times out.
Could probably change it out in ten minutes, I have never seen a rebuild kit for mine, but mine is an antique with "limited parts availability", per MerCruiser.............

 

[HT32BSX115]

Re: Maintaining mechanical fuel pump

I'm going through the fuel system from the pump backwards to the tank, checking for leaks, checking fittings, vacuum from the pump, etc. The manual suggests, during fuel system maintenance, to take the mechanical fuel pump apart to inspect and clean, and to replace failing parts as needed.

Is disassembling the mech fuel pump something that folks tackle? Or do folks prefer to just swap out the entire pump if they have suspicions about it?

It's very difficult to suggest a plan of action if we don't know what you're working on.....

 

[mkpj1]

Re: Maintaining mechanical fuel pump

I pulled mine apart. Pretty easy but I'm pretty mechanical rebuilding engines and carbs and such. I have a 84 3.0L merc with the old rebuildable unit. I think replacements are not. There really isn'tmuch you can do but clean the gunk out of it. The gaskets are strong reusable types in mine. Prior to rebuild (uh pull apart and clean like a carb) mine was pulling no more than 2hg at idle with a distal restriction as described in the sticky here. No more than that after over a minute Following the cleaning I was able to pull 6hg and rising after 45 seconds of restriction. Still somewhat weak but much much better than before. I had mostly air in the system prior and no bubbles/air at all after rebuild.

To me very easy and something that should be done regularly, if you can.

The main question is, how weak is too weak. According to the sticky posted here, it needs to reach 6hg in 10sec. I have not had my boat on the water yet to have a look see with WOT. Will let you know.