1987 6hp evinrude commercial won't stay in gear at high rpm.

[Jzfp34]

Took this 6hp motor to marine mechanic to fix this issue. Stays in gear at idle or mid rpms. He went thru lower unit , everything looked great. Went thru linkage and tightened it back up. He thinks there is a part missing under the cowling. He said nothing was worn in the gears and they lock in as they should. He doesn't understand why it will not stay in gear/pops out of gear. Motor is in great shape besides this so really want to solve and save this motor . Any help will be greatly appreciated!!!

 

[racerone]

Does the motor rev up smoothly at those high RPM ?-----------Does is feel like you hit something when it does this ?-----Have you tried another propeller as the hub could be slipping on yours ?----And lastly is the motor mounted too high ?

 

[Jzfp34]

The motor runs smooth all the way thru. The motor is in a test tank at a shop. Haven't checked prop but I will ask mechanic if he did. I was given this motor and told about its issue. So I took it in to be serviced before ever mounting it on my boat.

 

[Chinewalker]

Sounds like the hub is spun out of the prop. Easy enough to check - mark the prop nut and propeller with a line from a Sharpie. Run the motor and make it slip. If the lines are no longer aligned, you've got a spun hub.