Re: Problem With 2008 6HP Nissan 4 Stroke
Both forward and reverse gears are always turning whenever the motor is running. That causes significant motion and turbulence of the gear oil. The prop shaft is either disengaged (neutral) or mechanically clutched into one or the other of the gears. Dues to the viscosity of the gear lube (and the wear of all the parts), it is possible for the prop to turn slightly and/or slowly when in neutral. That is the case for all motors of all brands of this size category. The phenomenon will vary with the viscosity of the gear lube (which can be affected by temperature -- cold makes the oil "thicker", and the effect will be greater), and it will vary with the wear of the clutch dog, clutch lugs on the gears, bearings and bushings in the LU.
There is no braking or "park" mechanism to "freeze" the prop in place when the motor is running in neutral on any of the small outboards of any brand. Neutral is just that -- freewheeling. Many small OB's will show some prop rotation in neutral. We see that all the time when running motors on "muffs". That should not be enough force to significantly damage a prop if it contacts the bottom of a boat launch ramp. Yes, it might scrape a little paint off the prop, if someone is careless, and allows the prop to contact something.
But... if the motor is in fact in gear, yes, that can (and usually will) hurt the prop when/if it strikes the bottom. It can also do a lot more damage, including tearing up gears and twisting the driveshaft. The prop is never supposed to touch the bottom at all -- even when the motor is not running -- because the weight of the motor itself pushing on a prop blade could damage it.
So... to diagnose the shifter linkage yourself, see if the prop freewheels in neutral, and is locked in gear when in forward and when in reverse. If it does, you are adjusted OK. If not, you can adjust the shifter linkage through the access hole in the exhaust housing. The coupler is accessed after removing the large rubber grommet that plugs off that hole. The brass coupler has a single 6mm bolt (with a 10mm head) that can be unlocked to allow the shift rod and cam rod to be slid into the correct adjustment with each other. The complete information is in the factory service manual, available from any dealer, including me.
You mentioned that you sometimes could not shift into reverse. Keep in mind that the motor must be idling in order to shift. If the motor is not running, or if the RPM is too high, you may not be able to shift.
