Difficult to shift in forward w/o running

[Yadrif]

Hi All,
On a 1978 Mercury 20 HP, while turning the prop by hand it shifts between neutral and reverse without a problem. But will not go into forward.

Is this just becuase the engine is not started?

I'm having a fuel filter gasket leak that I think is keeping it from starting but am concerned about not being able to shift in forward while hand turning the prop.

Thanks for your help.

Thanks.

 

[rndn]

Re: Difficult to shift in forward w/o running

You really should not be trying to shift an outboard unless it's running.

 

[Texasmark]

Re: Difficult to shift in forward w/o running

You really should not be trying to shift an outboard unless it's running.

Sorry, but only Reverse. The reason is that Reverse gears, Mercs anyway have square gears, not sawtooth like Forward. When going to Reverse, you need to either have the engine running or rotate the prop as you gently move the shift selector to R. When the teeth line up it will easily slip in place.

F has an overrun clutch and is driven by sawtoothed gears on a springloaded clutch dog. Not a problem moving from N to F regardless of engine on or off.

Once in F, if you turn the prop CW from the rear, it will not rotate the driveshaft/crankshaft/ engine. It will just go click, click, click. If you attempt to turn it CCW you will encounter the full resistance of engine compression and you will have to stand up on the prop blade to get the prop/engine to move.

The purpose of the F gearing is an overrun clutch designed to let the engine go to N while you are underway and the prop is turning at the rate the water is pushing it as the boat goes forward. If it weren't for that, if you were at WOT and set the gearshift to N, you and your occupants would go over the windshield into the water in front of the boat as the prop would lock up and act as a gigantic sea anchor...........

Mark

 

[berrabbit5849]

Re: Difficult to shift in forward w/o running

My Merc Manual strickly warns not to shift into Rev unless the motor is running.