Vibration in reverse

[MEDIC151]

I noticed the other day, that I have vibration while in reverse. I don't know what causes this. The only thing that I could figure is, shaft out of alignment or bent. Any thoughts would be appreciated.

Medic

[purplepower]

Is there any vibration in forward? Is it a carb engine?

[MEDIC151]

No there isn't any vibration while going forward and it is a Carb engine.

MEDIC

[purplepower]

In reverse there seems to be more drag on the transmission. This can make the motor (worse with the carb version) chug and "shudder" at low speed, particularly in reverse. I would still check the balance of your prop and allignment of the drive just to be sure.
My carb runs rich at idle. This makes for a "lumpy" tickover even in neutral. I am going to work on this in the spring (our lake is still frozen). I will keep you posted.

[MEDIC151]

Thanks, I will check it out.

Medic

[outback-newbe]

My boat initially had a vibration when strating to go into reverse. What i found was that the dealership did not tighten down the nut on the prop shaft. It was out about 3/8". When i tightened it the vibration wend away. -not sure if yours is or not but maybe something to look at.

[james yarosz]

My boat didn't vibrate but I did find the prop nut loose(about 1 turn)after about 10 hours.