My motor WOT changes day to day

[rockymax]

I feel your frustration and exasperation and I wish that I had an answer that would solve the problem. If your speed is reduced (I assume you are using a gps for speed determination) when your rpms decline, it would seem to be a fuel flow or computer problem due to the variances and not a guage problem. Have you tried looking and/or posting on a Mercury owners forum, i.e. forums.iboats.com, marineengine.com, etc? You may or may not gain some insight to your problem. It might be worth the time and effort. I have learned a great deal on the Evinrude owners forum that has world wide owner participation including extremely knowledgeable marine engineers. I would recommend that you post your problem on this site and not indicate your engine is a Mercury, only an '05 115hp (http://www.etecownersgroup.com). You might find some insightful information. Keep us informed. Good luck!

[Alohatoon1]

He also told me that Mer motors wear over time and you have to reprop to adjust to the wear

that was perhaps the biggest piece of B.S. I have read for a long time.

[badmoonrising]

Yeah that's the biggest BS I ever heard.

[mjlyn]

jrboatin,

Did you ever figure out the problem?

[WaltF]

SomethAng aint right here..
i Agree, thats some sweet BS there...

[jrboatin]

Talked to another dealer, they are going to test drive boat then pick up for winter. I am hoping they find something, motor has been running at 5800 rpms last few days, but the dealer said it may run better cause of the cold air and water.

The tech did say 2 thing, one I did not think of, oil level. He said he likes to run the level just under the full mark. This way there is less
pressure in crank area working against the pistons. I kind of believe it so I check my oil level, just above high mark
so I will adjust and rerun soon.
Second he gave me the story of stuff on toons slowing me down, but I stopped him dead by saying I agree but my rpms change day to day. not go down down down cause of growing life form on toons.