Only Get Throttle When Shifting

[joey nathan]

'97 Mercruiser 3.0LX Alpha-OneGen-Two Yesterday when I go to leave the dock moving shifter forward only revved engine and did not shift me into forward. Reverse seems to work okay as that's how i returned to the dock. What would cause that? Remote is Mercury 3000...

 

[littlerayray]

When you started it did you disengage the gear and Rev it up sounds like the shifter isn't rein gaging from neutral

 

[81 Checkmate]

Did ya happen to have it in trottle only position. Pop the hood and move the shifter and see if it is moving on the shifter plate at the motor. If its moving then put it in forward and see if the prop is locking.

 

[joey nathan]

Both good suggestions - since yesterday I've pulled the remote off the side panel and disconnected the cables there and at the shift plate end If I remove the black plastic tube by the shift plate I can slide the cable back and forth no problem. Put the plastic tube back on and I can only shift to reverse - seems jammed up when trying to go into forward.

 

[littlerayray]

Need pictures

 

[81 Checkmate]

Did ya see how it was working before you took it all apart. Could have been just an adjustment at the shift plate. If you move the cable at the shift plate does the prop lock in forward and reverse?

 

[joey nathan]

Can't do photos today. But the reason I disassembled everything is because I couldn't get shifter to go forward. Would go to reverse every time. I don't think prop is locking in forward 'cus I can't get shifter to move forward enough. Possible problem is in the leg? What is the purpose of the black plastic tube by shifter plate?

Inside of remote mechanism looks fine - plenty of lithium grease on all parts. Replaced transom shift cable last month but have used boat several times trouble-free since.

 

[joey nathan]

No Title

So reassembled the remote and took a look at the lower unit and shift plate again. Prop spins freely both directions while in neutral but also spins both ways when shifted to reverse. While shifted to reverse however the prop will spin counter-clockwise and makes a clanking noise. Is this normal? Still can't shift into forward at this time.

Pics are of the cable linkages on top of the engine and I think everything looks as it should there.

I've got this sinking feeling that the lower unit is going to have to come off...

 

[Fun Times]

Only as a starting point test, Are you able to remove the shift cable from the plate going down to the drive then move the cable in and out by hand while having someone else carefully turn the prop by hand to see if it will lock in one direction and turn with a click the other direction. Then move the cable the opposite direction so that the prop will lock/turn-click the opposite directions.

The plastic tube is an Shift Assist Assembly for going back into neutral gear .

The Shift Assist Assembly assists the boat operator in returning to true neutral gear. Because of this, the Shift Assist Assembly will be installed on all Alpha One power packages produced after January, 1989. This Shift Assist Assembly will not provide any assistance if the shift cables are not adjusted properly. Also, the Assembly will not correct any existing shifting problems caused by worn or damaged parts. This Shift Assist Assembly can be added to any MC-l type stern drive (outside the serial number range given in this service bulletin) that has the short slot [7/8 in. (22mm) long] in the Lever Assembly (for shift cables) on the shift plate.

Service Bulletin 89-4

 

[joey nathan]

Turns out that I could not shift with cable removed from the plate. Pulled the stern drive and found set screw backed out of the shift shaft lever shown here (fourth picture down page). It was binding everything up and was a simple fix as nothing was broken.

http://www.sterndrives.com/merc/driveparts/GIMBAL HOUSING SQUARE_SQUARE UPPER SWIVEL SHAFT.html

Many thanks to all who gave tips, advice, and tried to help. Jon