May not quite feel like spring in some places, as of 12:30 MST & PDT (3:40 EDT, 2:40 CDT, 1:40 MDT), 46F in Seattle, 51in Washington DC), but here in Phoenix it's 83 heading for a hot dry summer of 90s & up by Tues, 4/19. Don't know about most folks, but we didn't do all that much boating in 2020 and not a whole lot more in 2021.
From the last fill up of 2019 on July 18th that year to the next fill up of 11 gallons on 3/27/20 we ran 28 engine hours. Our last day on the water on 7/27/19 I left the tank reading 3/8ths full which sat that way, with +/- 9 gallons in the tank until the next fill up on 3/27/20. The boat sat in storage for the rest of 2020 with a nearly full tank of fuel until our next local outing on January, 16, 2021. Between then and the end of 2021 we did our Erie Canal trip plus some local outings, total of 50.3 engine hours for the year, burning approx 23 gallons, adding 4 gallons to the tank on 5/29/21, and 10 more gallons on 8/9/21, leaving the gauge reading at 3/8th at the end of our first outing of this year on Jan 11th-12th, putting 4.5 more hours on the clock and a 5 gallon partial fill to the 3/4 tank gauge read on January 29th, finally topping off the tank with 4.1 more gallons last week on the 8th.
Meanwhile I had not serviced our primary fuel filter/water separator since May of 2019, two years and 11 months ago, roughly 155 engine hours and 70 gallons of fuel burned. So that PM item was due & completed on March 22, along with replacing the secondary fuel filter cartridge. Moisture absorption is not much of a problem in these parts with our dry desert climate, but excessive heat is, with temps inside the closed up cockpit already topping 100 deg. So, before adding the 4 gallons of fresh fuel to top up the tank (and eliminate air space) and after the above mention filter changes, I added the recommended 1 ounce to 20 gallons of Power Service brand "BioKleen" biocide treatment and the recommended 6 oz to 20 gallons of Diesel Kleen additive and cetane booster that I use regularly in my RAM diesel truck. Then hooked up my hose & bucket rig and ran the engine for 10 minutes at 1200 RPM to run some of that treated fuel through the engine. So once again, what's in your tank and how long has it been there?