Engine Reved and lost forward

[Wallyiii]

Not sure if this is a LU problem or what; mid 1970's Vnture Boat W/115HP OB Merc. Must admit poorly maintained LU; was running awesome then at 3/4 throttle crossing waves engine reved pretty high for a second then gained water again and pulled thru waves fine and then suddenly lost forward gear; thought it had jumped out of gear; I immediately pulled back throttle to idle and it died; started back up and when I engage forward gear it bogs down immediately and dies; same with reverse. AS it idled there was a contiunous clacking noise in mid to Lower unit. Towed to shore and took home where I pulled the LU off and really see nothing wrong. The fluid was dark and certainly low. Can low fluid cause this? I could free spin the prop beofre tearing down. Any help is appreciated. Also any advise on reinstalling is appreciated - looks and sounds a little scary with tubes and shafts. Wally

 

[Chris1956]

Re: Engine Reved and lost forward

It sounds like the gearcase is terminal. However, fill it from the bottom with some marine gear oil, until it comes out the top. Maybe you will get lucky. If the gearcase is off, turn the driveshaft CW with a pipe wrench. See if it moves smoothly

If you need help installing the gearcase, post back, or better yet, pick up a service manual. It sounds like you will need it for some other maint. items.

 

[swordfish25]

Re: Engine Reved and lost forward

I agree, sounds like the gear case is shot. Hold the prop and turn the shaft cw in gear, and see if you can hold the prop from turning. I spun the center of the hub on my prop, and acted like that except that would not keep it from turning over.

 

[Wallyiii]

Re: Engine Reved and lost forward

Hey I did not see these replies; I appreciate it. I have it resealed, and going back together but drooped the shift cam when sealing the shaft I have the lower unit on work table but not sure which direction the cam goes in. It can go in any number of four directions anyone know? I attached pictures of the lower end and how it is lying & another of the cam and how I think it is suppose to go in. Not sure if these came thru or not. i will be notified now of any replies - after truning on my email thanks again; WT

 

[saumon]

Re: Engine Reved and lost forward

From you pic, i think you figure it right. The stamped number goes up and toward the prop.