Mercury seems low on power.

[KramerSP]

2012 250 Pro XS SN 1B917123 on a Nitro Z8. A little history. When I first purchased the boat, with 3 people in it it would jump on plane and even have a little prop blowout and regularly hit 70mph with 3 on board and half tank of gas. Well, I've added 2 Talons and an extra battery since them. Prop is a 26P tempest worked by Mark Croxton and I have a new SSR HD hub. It's a dog out of the hole with just me on board and half tank of fuel. Needs forever to hit 70mph. One thing, fuel in the tank is a year old but was ethanol free and treated. I did blow my belt this season as well. Not sure if that would foul my plugs or not. Plugs are gapped and new this year from Don. Also, seems my throttle is sticky going back to neutral from forward and reverse. It has a hot foot. Should I move the 10"jack plate? Any suggestions? Not getting any alarms.

[Savage]

You need a different prop now that you installed the boat anchors. Try a Bravo1 XS 2015-2018 edition.

[EuropeanAM]

I would also suggest FRESH 87 octane fuel before making any changes. Year old fuel isn't going to result in peak performance.