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Backward Gears

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warren718

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I have a 1971 50hp Mercury outboard. Whoever owned it before put a gear in wrong or something. To go forward, you have to pull the shift lever to the rear and push it forward for reverse. Is this an easy fix or is it labor intensive?
 
Answer some questions.----------When you move the shift lever to forward , does the shift cable at the motor pull to the front ?---How long have you owned it ?---What colour is the control box.----Note -it is near impossible to assemble the gears wrong.
 
If you have a US Marine shifter (control) that is how they work (as assembled). They could be adapted to work with Merc/Yamaha/OMC by disassembling the shifter and turning the cam (so that it pulls instead of pushes the cable for forward gear).

So as racerone is insinuating, it sounds like someone was handy enough to install the control box (or swapped the motor), but either couldn't figure out (or didn't bother to try) adapting for the motor and left it the way it was set up...

OR did you install this motor on a boat that was previously fitted with a FORCE motor?
 
racerone said:
Answer some questions.----------When you move the shift lever to forward , does the shift cable at the motor pull to the front ?---How long have you owned it ?---What colour is the control box.----Note -it is near impossible to assemble the gears wrong.
Click to expand...

The shift cable pulls to the front of the motor in forward or reverse. The control box is a black merControl with a red handle. I have had the boat for about a month, but I haven't had it on the water yet.
 
Are you sure that you are looking at the shift cable here?-------------The shift cable is the first one that moves !--------Only the throttle cable moves as you describe.----Sounds like you have the 2 cables mixed up.
 
racerone said:
Are you sure that you are looking at the shift cable here?-------------The shift cable is the first one that moves !--------Only the throttle cable moves as you describe.----Sounds like you have the 2 cables mixed up.
Click to expand...

You're right. Upon closer look, the shift cable moves forward when the control handle is pushed forward, and moves to the rear when control is pulled back.
 
kimcrwbr1 said:
Your gearbox has the ratcheting clutch in forward. Hook up the controls and shift the handle into forward engine off and then turn the prop in both direscions, It should ratchet with the prop pushing water the prop spinning clockwise and lock going counterclockwise does it do that?
Click to expand...

Pushing the control forward, the prop turns counterclockwise and lock clockwise. Pulling the control to the rear, the prop does ratchets clockwise and locks counter.
 
1971 was a long time ago. Current engines of that HP have an overrun clutch with F gear and cogs for R. Current engines run a right hand turning prop. 90% of all props are right hand unless you have a counter rotating engine which is setup for dual installations only. Pictures you see of props are usually right hand turning.

On a right hand turning prop, looking from the rear, in F, the prop will ratchet (make use of the over run function) when turned CW. If you attempt to turn it CCW you will have to move the whole drive train to get the prop to move. When the drive shaft is driving the prop it turns it CW which is the same as YOUR putting CCW pressure on the prop itself.


Reverse has no overrun clutch because the usage and pressures don't require it. So it is made up of cogs on the shift dog and sockets on the R gear. The shape of both are square meaning that you have to have both lined up for them to mesh. For that reason, any time you shift into R the prop needs to be turning as you shift. If not turning (by hand or power) they may not line up and if forced will damage something in your shifting mechanism....per the service manual. Back in '71 they may have used the same gear for F and R. If so it too will ratchet but in the CCW direction and lock in the CW direction looking from the rear of the engine. Later on they decided to use cogs. Guess there was a reason.

On the cables, it's not rocket science. Disconnect your cables at the control or the engine; engine preferred. Move the shift lever and throttle linkages on the engine through their respective movements paying particular attention to where they are for the 3 gears and for idle and WOT.

Go to the control box and move the control to some position noting the movement of the cable at the engine. Line up the one that fits the function and install it. If your box is black with a red cap I think it is a single lever throttle shifter. Earlier models had 2 levers, the long one being the throttle and short the shifter.

The movement of the cable is dependent upon where it is mounted on the lever. If the lever pivots in the center and the cable is on the lower end, it will move opposite to the handle......aka push the handle forward and the cable extends...goes to the rear.

If the pivot is at the bottom and the cable mounts between it and the handle, it moves as the handle moves...push forward and the cable retracts within the sheath....moves forward also.

Recalling a couple of years ago when I was into mine, with the single lever the cam inside has one cable on the top and the other on the bottom, pivoting in the center. Meaning that if you put the handle forward, the shift cable moves first (that is a clue right there), retracts the cable and pulls the shifter into F gear. Continuing to advance the handle, the throttle cable extends and pushes the throttle linkage to the rear going from idle to WOT.

HTH,
Mark
 
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