lockdown clamp?? motor poping up in reverse

[Texas4x4]

Not sure what the technical term is but when I put the engine in reverse and throttle up the engine raises out of water. there are two locking arms but they do not stay locked does anyone have a schematic or an explanation of proper fuction.

the outboard is a 1985 merc 60hp manual trim with no jack plate.

 

[Moody Blue]

Re: lockdown clamp?? motor poping up in reverse

Sound like your reverse lock system is not working.

When in neutral or reverse the motor should be locked down to prevent what you are seeing.

When you shift into neutral or reverse, a cam in the lower unit pushes UP on the reverse lock rod that is visible at the front of the exhaust/driveshaft housing (midsection). The reverse lock rod activates a spring loaded latch mechanism that rotates and locks two "fingers" over the trim tilt pin in the transom clamp. Tilt the motor fully up and have a look underneath.

If the motor once upon a time HAD power trim, then those components would have been removed. I have seen motors where the reverse lock rod is so badly worn/corroded that it no longer is able to activate the mechanism.

 

[ajgraz]

Re: lockdown clamp?? motor poping up in reverse

On my 1978 70hp, that cam has to be oriented correctly or else it will not push the rod enough to lock it. It is easy to disorient the cam when doing an impeller change. If oriented wrong, all is OK except no reverse/neutral lock.

(Dunno if the same is true on your motor, just throwing that out there.

 

[Texas4x4]

Re: lockdown clamp?? motor poping up in reverse

thanks I'll look into the mis aligned or worn cam the fingers look slightly worn but still have a lock jounal machined into them. the springs are attached and I see very little corriosion. I suppose the only way to check the cam is to drop the lower unit again

thanks for your help and advise joining this forum is the best thing I've done since purchasing my first boat!!

mg

 

[couch229]

Re: lockdown clamp?? motor poping up in reverse

I just had the same issue.turned lowerunit upside down to get crud out and cam fell off.mine is a 79 70hp.anyway with the lower unit off the short splined shaft turned ccw,place the cam so that the ramp is facing foward,flat part of cam to the right.oh the controls in the furthest foward position.with mine i was good to go.you will know if you are off one spline oneway or the other as the lock will not engage.

 

[mike1245]

Re: lockdown clamp?? motor poping up in reverse

i have same problem but have noticed my rod is bent is that normal or it mine trashed