2003 merc 115 efi 4 stroke with no power

[idiggett]

i have a new 2003 merc 115 four stroke that has been at the dealer for 3 weeks beacuse it has no power above 3000 rps. they have changed everything on the fuel system with no luck. then they call me and tell me it is the fuel injectors (clogged) the boat has 20 hrs on it. the filter is pristine clean. but the inside of the injectors are packed with a paper like material. Merc tells me they dont warranty clogged injectors. (because they cant control the fuel i put it in it),that sticks me with a $400.00 bill on a motor that has had less than 200 galons of gas run through it. i think it is comming from somthing inside the engine after the filter. i have heard of three other 115s with a rpm problem related to the injectors. mers tells me no, your the only one....am I?

 

[Seapro1]

Re: 2003 merc 115 efi 4 stroke with no power

I have a 2005 Merc 115 4-stroke EFI and am having similar problem. No power when under load. On land with the muffs on I have no problem getting to 6000 rpm, but in water it would not go past 1500rpm.

I am still trying to troubleshoot myself. I called a mechanic and he said I need a $600 carb job. Funny thing is this motor is EFI, it has no carb....!

I emptied the gas in the in-line fuel filter cup and filled it up with Sea Foam. I let it run for about 20 minutes and then cut the engine off to fill up the filter cup again. The idea is to try to clean out the injectors. After doing this four times the engine seems to run good. I have not put the boat in water yet to know if it would still put out 5000 rpm under load.

May be you want to try the same route and see how it goes.

 

[sdsaw]

Re: 2003 merc 115 efi 4 stroke with no power

It sounds like both of you guys are in need of a VST(vapor separating tank) service (cleaning) and possibly injector(s) cleaning.

ideggett, Yes, injector issues are fairly common on most of the EFI motors, but can be avoided with proper fuel system maintenance.

Is your gas tank clean?

Do you have a 10 micron water/fuel separater filter?

These EFI motors are very sensitive to any kind of contaminants in the fuel that you run through them. Much more sensitive than the older carbed motors of the past.
Avoid gasoline that exceeds 10% ethanol.

Do a search over in the Yamaha/Suzuki section for "clogged injectors" and "VST service" and you will find discussions on this subject.