Reckless32

Sounds like this wire thing is a common problem. Makes me wanna check out all my wires just to be sure.

onesickpantera

iTrader: (1)

I've heard of several people having battery ground problems and lose 4-500 rpm. A friend of mine chased his tail for two weeks replacing spark plugs, plug wires, water seprators, etc. Turned out being a $6 ground cable!

LAKESIDE RESTORATIONS

Was there any difference in outside air temp & humidity?? Example good day = 60' outside Bad day 95' outside ??

vandeano

Make sure your not taking in water that you cant see. Maybe under the floor. I forgot to put my plug in (ya I know...dont say it ) but it wasn't until I open my engine hatch to see why my alternator gage was reading 0. Water was already going over alternator.

Pwrbt33

iTrader: (2)

Just a shot in the dark, if you have mufflers or silent choice, make sure they are opening all the way. If one is opening and not the other that will do that as well.

Good luck, keep us up to date.

John S.

Knot 4 Me

Back from LOTO. Heading down tonight to start checking things out. Boat is pretty consistant regardless of weather conditions. In the heat and humidity of summer I can still hit 4,700 RPM. Most recent run was done about 7:00 in the evening and the air temp was in the lower 80's. I can normally hit 4,800 in that air temp. Fuel was 1/4 tank and just me and my 12 year old son onboard. I'll see what I can find tonight. Only thing that has been acting up recently is my Corsa exhaust. Has been tending to stick every now and again but I flip the switch a couple of times and it will open up or close back down. WOT runs in the past with the exhaust closed never made that much difference in RPM. It is side-exit exhaust with baffles so it is provides more show than go.

Dave M

If you don't find anything obvious, I would run a scan on the motor.

Knot 4 Me

Agree. Got a friend that is a certified Merc tech. He is now working at the marina where I keep the boat, but the marina is not a Mercury dealership. Don't know if he owns a scan tool or not. The dealership he used to work for may have owned all the specialized equipment.

Dave M

I bought Diacom marine software. It was money well spent. With these new engines it's worth the $$ to buy a scan tool or some type of diag software.

http://216.230.203.183/marine/marine.htm

Knot 4 Me

Thanks for all the help, everyone. #4 plug wire was laying in the bilge. You can tell it was initially installed under the water hose feeding the manifold. When I tried to reinstall it in that position, there simply wasn't enough room to get the boot between the plug and the hose and get it to click in place. Not sure if the hose contacting the plug wire installed in this position is what eventually caused it to come off. I reinstalled the wire going between the hose and the manifold and it was a much more straight shot. RPM's and speed are back as well as the hole shot. Still weird that the motor did not vibrate or sound like it was missing. Boats definitely mask it more than a car does. Thanks again!!