your motor is designed to run on 87 octane fuel from the local gas station. adding octane booster will do nothing but lighten your wallet and lose a bit of power
unless your motor is designed with really high compression, you do not need high octane. your motor is NOT designed with high...
put more weight up-front.
on my underpowered Avanti, it required everyone up front to get my lard-butt out of the water on one ski.
as for drop in power. plug in Rinda and look for codes.
a new pump is only $175
look up Johnson pumps. you have either a Johnson F5B-9 or the slightly longer F6B-9. the longer (higher flow) F6B-9 is about $80 cheaper than the F5B for some reason. rebuild kits are reasonable too.
dont pay volvo for the same pump you can buy yourself.
here is a...
that looks like galvanic corrosion. something is literally eating the aluminum.
check your electrical grounds. none should be using the boat as a ground.
For a motor manual, go here. https://publications.brunswick.com/
As far as a boat manual, only about 12 manufacturers (out of 200,000 manufacturers over the past 100 years) have an actual manual, other than the 4-page safety brochure listing the servicing dealers
Take a boaters safety course
By clean....use 150 grit and make the terminals shiny enough your mother in law would eat off them
If the cables are crunchy, replace them
When done, seal the connections with marine electrical varnish
When I had to rebuild my ex father in laws boat due to live well plumbing. I spent a day with a small pick digging in the carpet to find the screws. Then another 2 days pulling the boat apart, finding the screws I missed
