2001 mercury optimax 200

[Mlivoti]

Just installed with 240 engine hours on 20' gw. Engine runs all the way to wot on earmuffs with no issues. Under load in water it won't go past 1600 rpm without stuttering. Have to throttle back and engine runs fine in idle. Can't get on plane. Engine warning light on smartcraft has continous beep.
Replaced all filters, cleaned fuel water separator. Replaced low pressure fuel pump. Tested air pressure. Tested engine on an auxiliary fuel tank with fresh gas same issue. New waterpump, waterflow is warm not overheating. Any ideas?

 

[Faztbullet]

Engine runs all the way to wot on earmuffs with no issues

That's a good way to do a quick disassembly in the driveway:nono:......Did you prime the oil system?????

 

[Mlivoti]

Engine was repowered in a shop and tested there. I assume oil system was primed when they tested but I'll double check. Could that cause this issue?

 

[Faztbullet]

Yes...could be in guardian mode...

 

[Mlivoti]

Would it still throttle past 2000 rpms on earmuffs with guardian mode?

 

[Faztbullet]

yes as no load on motor, it will rev to WOT on 3 cylinders with no load