Prop Spins but No Reverse on 1970 65hp Mercury

[gciccol]

I have a 1970 65hp Mercury on a 16' Starcraft Super Sport V, deep V aluminim boat.

I lost my reverse today. The engine was running fine all day. When I put it in reverse, the engine rev's very high, the prop does spin strong in reverse, but I don't go anywhere. Forward and neutral work fine.

Does this make sense? As I'm new to the boating world, I don't know if this is a problem with the lower unit, gears, transmission (?).

BTW: I don't know if this helps you but I did change the gear oil before I took it out. The old oil was slightly milky so I know there is a minor water leak. I did not run it very long or hard though today.

Questions:
1. Does it make sense that the prop would spin in reverse but I don't move.
2. Any suggestions or a link with instructions on how to check it out would be appreciated. (I did review the forum for similar problems but didn't understand the answers given to similar posts).

Also, any thoughts on what this might cost to have a mechanic repair it would be appreciated. I'm not in a position to spend a lot of money so if there are any detailed instructions on fixing this problem for a "do it yourselfer" would be helpful.

Thanks for your time and assistance.

 

[road.ripper]

Re: No Reverse on 1970 65hp Mercury

Re: No Reverse on 1970 65hp Mercury

Hi im have the same engine and i am in the same boat both as in new to outboards and on a budget.
my engine is a 1970 4 cylinder 650.
Im in the middle of what i thought was a simple problem and has now become a lot of work but with the help of alot of people on this site my work is progressing well. after i get the top end done i will need to work on my lower end aswell.
look for my posts if you ever need top end or electrical details .

As i have read, these engines are great if taken care of .
good luck with your endeavor, you will find lots info here, if you need parts or a place to look for them just ask , i have been lucky finding parts cheap that i thought i would have to buy new .

road

 

[gciccol]

Re: No Reverse on 1970 65hp Mercury

Re: No Reverse on 1970 65hp Mercury

Thanks for the reply. I may take you up on the parts offer one of these days. Good luck with the rebuild, you're a braver soul than me.

 

[Moody Blue]

Re: Prop Spins but No Reverse on 1970 65hp Mercury

I lost my reverse today. The engine was running fine all day. When I put it in reverse, the engine rev's very high, the prop does spin strong in reverse, but I don't go anywhere. Forward and neutral work fine.

Does this make sense?

In a word, no. If the prop is spinning in reverse and you are not tied to the dock or have an anchor out, then you should be moving in reverse . Quite possible that the prop is spinning (not strongly) due only to fluid friction in the lower unit. That would cause the engine rpms to increase (no load) without you moving. The gears aren't actually engaged.

Remove the motor cowling and have someone move the gear selector from neutral to forward to reverse while you watch the shift linkage on the motor. Its possible the shift cable is not moving properly which could mean a damaged control box.

 

[gciccol]

Re: Prop Spins but No Reverse on 1970 65hp Mercury

Thanks for the reply. I'll check it out. Sure would prefer a broken cable to replacing gears. Take care