OMC 800 shift problems

"1978 OMC 800 / 5.7L Chevy / G

"1978 OMC 800 / 5.7L Chevy / Glastron/Carlson - Last time out, left launch area at idle speed shifted to nuetral (to get a beer from the cooler) then throttled forward but drive wouldn't engage - forward or reverse (motor revs freely). Adjusted cables according to manual - no help.

Just dissassembled lower unit. Everything in order - no burrs, nicks or damage to hydro assist shaft, clutch dogs appear in good shape (not rounded off) What's the problem?"

Did You dissassemble the lower

Did You dissassemble the lower unit before or after this happened?
Is the engine getting cooling? If not the intermediate shaft splines are probably gone.
Broken shift cable from lever to engine?

Thank you for the quick respon

Thank you for the quick response! Dissassembled after multiple cable adjustment attempts. My thought was the clutch dogs were toast but that's not the case. Temperature gage reads normal - no problem with cooling. Intermediate shaft splines as new and cables/levers/gear/rack system all functional. I did notice that shifting effort became difficult (required more force to go from nuetral to forward) before this happened.

Oil level correct and no water in lower unit. I've been trying to dissassemble hydo assist unit but cannot rotate the top off (using needle nose pliers in removal holes). The cylinder doesn't seem to move freely over piston (?)and I can see some scoring on the I.D. of the cylinder. I heard that there maybe a kit available to convert to a full mechanical shift ? I've also heard that idle speed may effect shifting ? Motor idle speed is set at 850 RPM as I had some problems stalling from launch area when engine is cold.

"Your assist sylinder sounds t

"Your assist sylinder sounds to be the problem Although it is supposed to be 'not serviceable' I have pulled quite some appart and made them work again in my time. When they work, they are great, but You have to be careful with gearoil and change after no more than 50 hrs, a little depending of use. Try to get Yours appart, clean and reassemble. then change gear oil from 'Hi Vis' to OMC/BRP Ultra HPF. This oil is semi synthetic and handles loads and wear much better.
Another thing is to get Your idle rpm down to 650. Just get Your engine to operating temp before starting maneuvering."