I purchased the boat this spring. Like the title says I have one drive(1990-450hrs) that will not go into forward after a long run. If I shift it into REVERSE then all the way forward it will engage 99% of the time. I got the boat out of the water last week and on the re-entry the drive came out of gear. I pulled the sticks back so it was a smooth landing

Makes docking hard after boating

Jim,
have you check your shift linkage adjustment. The barrel with the cotter pin holding it in.. Remove the pin, pull the barrel out. Now shift the it into rev and back to neutral, motor must be running to do this or the linkage will bind up.. When the drive is in neutral the barrel should line up with the holder.. if not adjust it so it does. That will center the linkage and give equal throw for fwd and rev. If that doesnt do it.. the slot adjustment will give you more or less throw.. Too much and the shift fork will rub on the brass ring on the gears.. not enough and it will not go all the way into gear.
There are a few old threads on how to do this.. do a search.. Your linkage may be stretching or the cable from the transition block to the drive may be on it's last leg..

Hope this helps.
Dick

You probably have the old style 3 groove clutches and their worn out. Upgrade to new style 6 groove clutches and shift forks. Used ones work well too. Lap them in with valve lapping paste. Make sure all lapping material is removed. It will shift smother and faster than before. I have 2 sets used. Steve 925-389-6345

Check the linkage and detent ball behind the back cover on the drive. I've had to replace both of mine because of hard shifting. One would not go into forward at all. It never came out of gear though.

Thanks I will let you know what I find out.
I

if the gears and clutches are orginal the new six grove clutch will not work on your unit.

past due is right, you will need to go back to the merc service bulliten and get the right part #, and then see if there are still any avalible, you may get lucky and find one.