904 won't go into passing gear...

Actually it's more like 3 steps to adjusting the kickdown. Very simple job. First you need to make sure when you floor the throttle the carb is actually going wide open so get a buddy and have him floor it and hold it there (engine shut off) and you try pushing the throttle farther by hand. If you can't move it more the adjustment is ok. If you can move it more loosen the 7/16 head nut that holds the throttle cable to the mount and adjust it so it does pull the carb wide open wide open. If you found a problem there you probably fixed the kickdown also. If the throttle pedal adjustment was ok just adjust the linkage leading from the carb. to the trans. a little at a time, test driving it after each adjustment until you get it where you want it. Look at the linkage on the carb. good and you'll see the more throttle that is applied the farther the kickdown linkage is pushed back.

Take slack out of the linkage if it shifts too late and has excessive passing gear.

Remove slack if it shifts too early and has no passing gear.