2005 Yamaha F60TLR won't plane out, or go over 4000 rpm

[crabbin fool]

Yamaha 60hp 4 cycle with low hours and most of those are idling. I put the boat in and it starts and runs fine, but shudders and won't plane out. Warning horn works, but it didn't sound. It just had an oil change and it pumps water well. Prop is clear. I replaced the plugs, fuel filter and strainer. Back in the water, same issue.I pulled the intake and vapor separator looking for a clogged hose or dirt in the separator tank and found very little. A piece of the gasket to that tank was in the bottom of the tank though. The float controls the fuel flow ok, that filter and the injectors look clean, I cleaned throttle body butterfly. Any suggestions? Other than the gasket, I would like to find a problem but so far haven't been able to.

 

[crabbin fool]

Update: I disassembled the primary mechanical fuel pump, found some dirt and replaced the diaphragm. I changed the water pump impeller and base plate. I am soaking the injectors in a diluted solution of injector cleaner and have added injector cleaner to the fuel. Am I missing anything? Should I replace the hi pressure fuel pump? I see there is one that costs hundreds and one that is like $18. ???

 

[99yam40]

Monitoring fuel pressures to see if there was a problem with that and sending injectors off to have them tested and cleaned would be best

 

[crabbin fool]

I wired the injectors to the rail, faced it out, away from the engine and cranked the engine over. They all sprayed the same. OK back in the water today, and it runs really good. I was surprised to find that with the cover off it runs right up to 7000 rpm. Not good. But anyway, it planes out now and runs great. I wish I knew what I did to fix it though. Thanks for your suggestions.