Posted some on this last year, hasn't been resolved. Filters changed, injectors pulled and flow tested. Good compression on all cylinders. Local mechanic supposedly ran diagnostics and found nothing. Shop is a couple miles from our place on the lake, not a lot of faith in their capability. Motor starts as it always has, normal power low end. After that, it doesn't change from half throttle to wide open throttle. Fuel usage has doubled. Guess I need to make a run to hydrotech. Tired of having parts thrown at it without a fix. Owned it for 10 years, always done 100 hrs. Service. Plugs changed, no difference in performance, plugs all look the same. 780 hrs.