Sudden loss of RPM's on 2010 180 Challenger

[erkser]

Longtime lurker, but first post. And of course with an issue.
I have a 2010 180 Challenger, 255hp. While running down the lake I experienced a sudden drop in RPM's, down to 6068. Felt just like pulling the throttle back. Now that's all it'll do. At WOT all I get is 6K rpm's. Boat runs fine other wise. Idles well, throttle response is good, just won't get to the @7800. There are no warning lights, error codes etc. displayed. IT has 67hrs total on it. During my search I ran across some info abaout the IAT (intake air temp sensor). Some stuff about issues, a recall, etc. Mine has the "green" sensor, open air type thermistor. I ohm'd it at about 75 degrees F and read 1500 ohms. Is this in range? With a little warm air the ohms decreased as expected. Could this sensor be bad with these readings? Could/will this cause the issue I'm experiencing? Any help or direction would be greatly appreciated.

 

[jalers01]

First thing I would check is the throttle cable and make sure it not loose at the throttle body. Not sure about the sensors but this was my issue when I first got my boat that both engines did not line up at same rpm.

 

[pvamax]

Could be as simple as a plug going bad, mine did the same in first run last year. Typical early season blues. Changed plugs, all good.

Or it could be as bad as supercharger failure, and you need to pull the motor to clean out the bottom end! Sc failure will also leave rpms at wot around 6k.

Time to dive in...

 

[JPass]

When was the last time you changed your plugs? These 4tecs are very picky about plugs. You can check the SCer by removing the inlet tube and seeing if you can spin the impeller by hand, if you can, then the clutch pack is slipping.