Mercury V-140 International (Saltwater) suddenly wont rev over 2200rpm

Hi there, sorry if I have posted something commonly posted but so far I did not find anything.

All of a sudden yesterday, while at 3/4 power the engine dropped down to around 2000rpm and will never rev any higher since.

- Plenty of oil in both tanks
- No alarms
- Plenty of water through the telltail and water temp is all ok
- I rebuilt the fuel pump a few weeks ago and has been working perfectly since
- Attempting to rev from control box or control lever with couling off results in the same issue
- Fuel filter replaced recently
- Starts ok without any throttle
- Idles ok initially but I would say that it does stall after a little while idling now

V-140 2.5lt Carb
Serial 1V041534
Model 1140422DF


It is possible this engine has a high rev protection that may have malfunctioned ? It's wierd how it starts fine and runs fine (I can motor around but only up to 2000 revs) but simply wont rev high. I could always rev high in neutral also but that also is limited too.

cheers

Mark

Check for spark on all cylinders.-----Sounds like it is running on 3 of 6 cylinders.

cheers, I was going to replace plugs this week anyway, so I'll check that out at the same time.

Of all things, it ended up being the bolt on the throttle arm coming loose and falling off. Looks like it is only held by locktite and not a nut on the other side

I had some photos but they keep being rejected when I post them.

Hooray

Thanks for posting your followup. Usually folks solve problems not knowing they did so since the original poster gets their answer and is gone bye bye, which is of no help to them in trying to sort out answers for problems in the future. Glad you got her fixed and a simple thing at that.