Mercury 700sci problem
 

In keywest and trying to fix my 700sci. Engine will hardly run. Smartcraft reads boost valve error and ICA error. The engine is running rough and buzzer will not shut off. Anybody got suggestions. My boat is a 42 Fountain and has the name SLATER on the back. If anybody knows how to fix this my cell number is 901-335-1203. Thanks Andy Smith

Is the Mercury Racing truck not there?

Do you mean IAC error.........Idle Air Control valve? Not at all familiar with 700sci's and don't even know if they have IAC's??? Heard just yesterday about a 700sci supposedly having an IAC problem of some kind that caused a short in the engine wiring harness and melted some pins in the connector. Don't know what the symtoms where when it failed and don't want to send you on a wild goose chase, it's just a wierd problem that might be tough to find. If they do have IAC's and the valve is stuck partially open it could be a problem. If there is an IAC try unplugging the wire to it and see what happens. If there is an IAC it should be on or near the throttle body. If it does use an IAC and it gets unplugged it might be a hassle on starting and warm up and maybe also at big changes in engine load like when shifting in and out of gear?

Had a friend with 600sci burned up some wires and 2 computers and 2 iac valves
had to stop using deep cycle batteries

It does read IAC. I am still in keywest if anyone can offer help.

go find the NorTech trailer.. those guys will try and help you out.

Had the same problem twice what it is the computer will short out and tell the IAC valve to keep running until it burns up the plastic will actually melt out of the motor. I was told by one mechanic and mercury engineers it is the deep cycle batteries fountain installs. What I had to do was replace the ICA and computers and change the batteries. The batteries can only be starting not deep cycle or anything else.

My batteries always had a good charge in them. It would happen at the end of the day during a poker run where the motors were running all day. My mechanic said he saw this problem with a lot of Fountains. I didn't learn about the batteries until I lost my second computer.

Can someone explain what the battery have to do with the IAC? I know the IAC is a elecrically powered mechanical part that is constantly moving while the engine runs and just figured they were prone to failure.

I had a IAC go bad on my old Eliminator and one on my 42 Fountain but never on my 38 Fountain. The eliminator had starting batteries, the 38 had a starting battery on one side and deep cells powering the other side. My 42 has the original betteries, but I am not sure what if they are starting or deep cell.