Evinrude 115 FICHT: Backfires and Rough

[rustyscrew]

I have a E115fpxeec 1999 115hp evinrude ficht.

I just started it up to test it after replacing the low pressure fuel pump diaphragm. It was not good. It revved higher than it should. Sounded like it was missing a cylinder or two then stuttered and backfired a number of times and stalled. I didn't investigate further because it was dark and raining, but before I resume I am open to suggestions. Any ideas? Sensors? Bad Injectors?

History:
I got water into the engine that went past the water/fuel seperator in June.
I had it serviced by a mechanic ($850), but when I got it back and hooked it up the the fuel tank, there was a vacuum in the pickup.
I think this damaged the diaphragm on the low pressure fuel pump and I couldn't keep the engine running without hand pumping the primer.
I took it to another mechanic that is supposed to be the best. $2000 more later I have a broken motor still. They replaced the VST and fuel manifold. They were about to replace the injectors but I took the motor back because new injectors are $650 each.
I opened the low pressure fuel pump and sure enough it had a hole in the diaphragm.
I replaced it and that is where I am now....I was optimistic it would be the final fix, but now it runs poorly and backfires.

 

[aerobat]

Re: Evinrude 115 FICHT: Backfires and Rough

sure you have the correct spark plugs - and correctly indexed ? the fichts are very sensitive to this

 

[Bosunsmate]

Re: Evinrude 115 FICHT: Backfires and Rough

injectors are half that each, look them up on marine engine .com.
Sounds like its running lean on some cylinders. Pull the lanyard line, clean the plugs, reinstall and then hold the starter for about two burst of four seconds. see which plugs a wet with fuel or a dry (er)

 

[rustyscrew]

Re: Evinrude 115 FICHT: Backfires and Rough

Bosunsmate. Thanks. I thought the same thing too, but there are two things I learned. Those injectors are obsolete and I called about 4 different distributors including one of the central ones and they are all gone with no replacement expected. Secondly, according to the mechanic the injector that is supposed to be used (I think because of problems with 5000770) is 5004477. These cost: $600 and are also obsolete.

I like the idea of turning it over without spark to see where the fuel is or isn't going. The mechanics replaced the plugs and indexed them, so I really hope they used the right plugs. I know the FICHTS are super sensitive to that. Come to think of it, they did accuse me of having the wrong plugs in....that were installed by my other mechanic, the engine ran great on those. So maybe that is it.

What I wouldn't do for a good mechanic right now. Fortunately for me I enjoy solving these problems.

Thanks!