Need some help with how many MPG/GPM? My buddy just bought a 89 18ft Wellcraft CC w/ same yr Johnson Seahorse 140. I think one of our first trips is going to be on the BIG lake and I wanna make sure we have enough petro.
I'm pretty sure the 140s of that era were loopcharged motors, and they are thirsty beasts. Expect about 2-2.5 mpg. And don't trust the fuel gauge on a boat you've just bought and have no previous experience with.