My dad and I fish with 92 stratus bass boat with a 150 Evinrude. We are having a issue with fuel delivery. So we run on the port tank just fine pump the primer bulb and in a few pumps it gets hard and runs fine. This past Sunday we were running low in the port tank so we switched to the Starboard
tank pumped the primer bulb and the buld would never get hard the engine would crank, but as soon as we would take off it would die! Any idea why one tank would prime completely fine, but the other tank will not?

It's sucking air somewhere.

Those boats have an anti-siphon valve in them I believe. Have to take the fitting off at the tank and "knock" the ball out or replace with another valve.

We haven't had a chance to tear into it yet. We are mainly trying to find a good starting point being the tank is full of gas I know we can rule out the primer bulb being it works on the other tank perfectly! I can't remember if the tank has the anti-siphon valve in it or not. we had both tank out not long ago but didn't pay much attn. to it at that point!

I had a similar issue, replaced the fuel line and primer bulb from tank to engine, and it fixed it. $40 but be sure to get one that has enough line to make the connection all the way.

Did the boat have two tanks and did the bulb work with only one of the two tanks also?

one tank, I believe the issue was with the fuel line decompressing when the bulb was pumped. Sounds like your trouble tank could have a bad line. I was told that it's from alcohol in fuel. I only purchase non-ethanol, but bought boat used. It is an 87' evindrude XP150.

This or the fuel line has gotten old and thin and when you demand more fuel, it is sucking the top and bottom sides of the line together and starving it out. I had that happen and it was an absolute pain in the butt to figure out. Replaced the fuel line from bulb to tank, never another problem. Always start with the cheap stuff first and fuel line dont cost much.

Do you have portable tanks with quick connect fuel lines? Mine does and the cheap quick connect on the tank end will go bad and not look bad. If you put your ear down to it while someone else primes the bulb you can hear the air sucking. It idles fine but when the fuel demand increases it bogs down or dies. I bought a handful at Academy for $5 each and keep them in my boat. The one on the motor end of the fuel line never has failed, I guess because it hardly ever gets removed. This is my issue, hope it's yours because its and easy, cheap fix. Yours could be the tank half of the connection.

Not portable tanks they are built in behind the seating compartment(a massive pain to work on). Honestly I'm not even sure how the lines runs I know when you change from port to starboard an actuator moves and I assuming blocks of one tank or the other just like the vents in a car!

My ranger done the same thing. I replaced lines on both tanks and ran a new line from the valve to the engine. Good to go now.