2004 Merc 115 EPLTO high RPM issue

[group24]

I have a 2004 Merc 115. At cruising, about 3k RPM the boat runs great. If I bump it to around 4k, there is hesitation and then the RPM drops down to around 3k, maybe 3,200 tops without touching the throttle. I have been told this could be an impeller issue, maybe a thermo, maybe something else? Any ideas?

 

[ddennis]

Re: 2004 Merc 115 EPLTO high RPM issue

Welcome to Iboats!. I have the little brother to that motor...sounds like the mechanical advance isnt working properly. I don't have my service manual here with me..but one of the Guru's should be along to chime in on it...

 

[group24]

Re: 2004 Merc 115 EPLTO high RPM issue

Well, problem is that it gets to 4k, but almost immediately hesitates then drops down. Another guy I was talking to mentioned that it could be a water flow issue, possibly a worn out impeller, maybe a thermostat. I ran fresh water through it and water is coming out all the holes it's supposed to, so it doesn't appear to be blockage. My guess is that its one of the items mentioned above but was hoping someone has run into this before.

 

[alanaexall]

Re: 2004 Merc 115 EPLTO high RPM issue

if its a 4 stroke efi, i had the same problem. turned out to be one of the fuel injectors

 

[group24]

Re: 2004 Merc 115 EPLTO high RPM issue

Unfortunately no, its a 2 stroke.