Fuel flow for Yamaha 4 stroke . .

[Quackerbox]

Check prop hub too.

I'd think if the hub was slipping his rpms would jump each time it slipped

[KDinTX]

Just went through this, didn't have time to do it myself so we took it in. VST filter was clogged, fuel canister filter and pre filter were changed, fuel injectors sent off to be cleaned and fuel system flush along with oil changes for motor, lower unit and impeller, ran about $1200 or so. Boat was doing similar to what your describing, would run but didn't have the power it used to, and seemed sluggish. The ethanol gas is terrible on the small filter screens on these motors. I had rebuilt the injectors last year as well as other filters etc, but it didnt seem to fix all the issues. The VST was the main issue as well as injectors needing to be cleaned again.

[Sharecropper]

Update - took it Premier marine in Jasper . . It was the VST, lot of junk . . Cleaned tank, replaced screens (6) . . $400 . . Runs like a top . . First time in shop in 10 years . . Amen

[White Falcon]

Glad you got it fixed!