1958 5.5hp cd-14 no idle, motor or gas can.

Have a 1958 johnson cd14 5.5 and it runs good at 3/4 - WOT. I have to start it at 3/4 throttle, i can't get it to idle at start or below, hard to troll that way. After a while of trolling the motor seems to be loading up, its hard to start within minutes of dying when i turn the the throttle down to far. When i say hard to start i mean it takes more than 2-3 pulls. After a while the tank seems to build up a lot of pressure, load and seems long when open the cap. How much pressure should there be in the tank? The tank leaked and somme one resealed with cork, when its really hot out, the tank leaks alittle on the top,, so i store with the cap loose. Usually starts better after i rellease the pressure, coinceindence? Rebuilt the carb and replaced the plugs champ "6"s, the book called for 8s but repair book called for 6s. New needle and float also. Have noticed it looks like there might be fuel vapors coming OUT of the airsilencers/carb. Still has dual feed fual line. Any ideas are appreciated. Also at WOT the shifter kicks into nuetral, any ideas other than bungee cord?

Re: 1958 5.5hp cd-14 no idle, motor or gas can.

When you rebuilt the carb did you remove the core plug on top of the carb and clean the low speed passages in there?
Where do you have the low speed needle set at, 1 1/4 turn out from lightly seated?
The tank is not vented and will build pressure if the cap is tight and left in the sun. The gaskets under the handle assembley were cork, maybe yours is defective allowing it to leak.

Re: 1958 5.5hp cd-14 no idle, motor or gas can.

If it's kicking out of gear at WOT, could be shift linkage out of adjustment/worn, or more likely, a worn clutch dog/forward gear.