I have a 1955 Johnson 25hp. Once I start it up it will idle just fine for a little bit. After that the motor will rev up like the throttle was opened all the way up. Then the motor will just die on me. I rebuilt the carb after I started having this problem, and I do have a good pressure tank. I thought that by rebuilding the carb would fix it but it hasnt. The float is set right also. I just cant seem to figure it out. Do you have any advise for me. I would greatly appreciate it. Thanks Steve