Backfire by fuel pump

[jastacey]

I've got a 1987 85 HP force (Model # 856X7A, SN-2935 ), The problem is when I have the engine at idle it wants to backfire in the area of the fuel pump, It sounds like a sneeze, and the area is pretty oily, I pulled the fuel pump and didn't find any ruptured fuel pump gaskets, but the gasket behind the fuel pump was pretty brittle, when I pumped the bulbed for the fuel line it never really got hard, could it also be a bad puddle drain gasket, or could it be the gasket on the fitting that the fuel pump bolts to? When the engine was run at 4000 RPM it kinda din't have the power that it once had

 

[scotiany]

Re: Backfire by fuel pump

Why don't you just buy a fuel pump repair kit at NAPA and install it. A whole lot easier to do than those other procedures. Just replace the gasket and diaphragm and don't mess with the other parts in the kit.

 

[USNAVYMM2]

Re: Backfire by fuel pump

Have an 1985, 85 HP. Besides the fuel pump problem, it's a good idea to replace the fuel line & pressure bulb. WalMart has universal kits (the fuel line is 3/8" diameter) for about ten bucks. I found out a few things with this the hard way. Stranded 4 miles from the boat ramp at 11:00 PM is no fun because of a deteriorated fuel line. No pressure on the squeeze bulb is a good indication of a bad\weak fuel pump diaphragm.

 

[jastacey]

Re: Backfire by fuel pump

Well... the problem was a blown transfer port gasket on the # 2 cylinder, last year I changed out the fuel lines as they were shrunken and hard, that made a big differance as the fuel flow was restricted, I changed out all the transfer port gaskets, and the other 2 were very soft & spongy ... so it was just a matter of time before those let loose. As a note when you buy a fuel pump rebuild kit, you still need to purchase the gasket that is behind the fuel pump assembly, as this is not included in the gasket kit, this needs to be changed as this seals the connection between the two parts.