1988 johnson 140VRO won't plane on water

[rusltn]

I have a 1988 welcraft CC fisherman with a 1988 johnson motor. Just bought this boat. This boat has new power head never in water but has sat for 5 years with owner starting maybe once a month. had new water pump and carbs rebuilt and new gas. took it out and when throtle up it starts to go then it sounds like a spun prop at about 4000rpm. i bought a new prop and does same thing. sounds like it goes into netural before leveling out the boat. can the lower unit cause this???
thanks

 

[oldcatamount]

Re: 1988 johnson 140VRO won't plane on water

Sounds like it's not fully engaging in forward gear. Try disconnecting the shift control cable and manually shifting to forward and see if it still does it. If so, an adjustment of the shift cable would help. If not, then it would likely be the clutch dog in the lower unit is worn a bit. Caused from moving the shifter into gear to slowly and rounding over the dog ears.