I have a Johnson 25 hp outboard that only runs on choke. Any suggestions

Yep. it is starving for fuel. The choke is creating a huge vacume differential & is causing fuel to be ''pulled'' from the fuel source. If the fuel source was free flowing it would run on a regular vacuume.

Check ALL lines & hoses for obstructions. Try ANOTHER tank source. Look at all points for screens, filters, & sharp angles in the fuel lines that could cause a small amount of debris to cause a fuel blockage.

Also, DON'T overlook the fact that MAYBE u put the motor up for storage & did not drain out all of the fuel, thereby cause the fuel to dry out & gum up the small fuel passages in the carb. This will require cleaning out the complete fuel system.

if it only runs with the choke closed then you are not getting enough gas.
First: is the squuze ball hard on the line coming from the gas tank? if not change the ball
Have you checked the screen on the gas line on the motor?
You have a carb motor so there is no adjustment on the high speed jets so it seems that you should maybe pour some carb cleaner in wih the gas. After awhile it may clean out the varnish .

check the fuel pump diaphragm

clean the carb

Clean the filter, carb (main jet) and make sure the main jet is properly adjusted. Back it out until it runs better. Once it is running well, lean it out until you get peak rpm, then back off 1/8 turn to avoid running hot.

Make sure the air inlet valve on the gas tank is not clogged.