23 year old Honda Harmony HRT2162. 21" deck.
It's been through three sets of wheels and the piece of sheet metal that covers the belt rusted and I replaced it when I replaced the belt, but other than that it's basically just had the oil changed every season.
Mowing season here starts sometime...
I have never used a fuel additive that improved performance or increased engine power.
I have no idea how degraded fuel which mainly occurs through oxidation and evaporation of more volatile components can be fixed by an additive. At best you might add back some of the volatiles that were lost...
I have a 22 year old Honda mower than has never had anything but regular pump gas in it except on the last mow of the year I run a tank of Tru-Fuel 4 cycle gas (or similar) in it before I put it away for the winter.
I've never used any gas treatments and I've never had any fuel related issues...
As the filter media loads up with use of course the pressure differential across the filter will increase with time. Every filter will show this behavior as it is used.
You state "Only way for them to be moved apart like that is if there is "enough" Dp across the filter causing the pleats to...