transmission problem.

[arrowheadsaver]

I read all the transmission threads and I have changed the plugs out (but have not run it since. too cold)  I noticed a thread about the prop turning with engine off, but it never specified if it is supposed to, or if it is to lock up.  I can turn mine with engine off, and with it in forward and reverse. Am I screwed. or does the key need to be on?  Please give me better news than I am expecting.  It ran just fine last year, then I winterized it, took it out ran it for about 20-30 minutes and back at the dock it started making noise and shaking a little bit.  It sounded like I was hitting little pebbles with the prop.  I used Mobil 1 merc V for fluid, and I noticed it was about 3/4 inch low when warm.  Will that do it? Any help please.

[blindside]

Does the whole shaft turn when you turn the prop or just the prop turn?  If just the prop, replace the prop key between the shaft and the prop.

[arrowheadsaver]

Its the whole shaft.  I started it up with the fake a lake today, and it seemed to run quieter with the new plugs.  I put it in gear and did not hear any noises, so I just got to go to the lake and put a load on it for final testing.  Hopfully it was just plugs.

[HCollado]

Curious...

Did you switch were you normally buy your gas? Did you buy high octane gas? Ethanol gas?
 
My boat did this two years ago and it was because I had mistakenly put regular gas. Drained it, put high test and new plugs and back to normal. I had even changed the prop thinking I had hit something and it was out of balance.

My two cents worth.

[arrowheadsaver]

Changed out the plugs, and added fluid to the tranny.  It runs really good now, no noise.  Still don't know if it was the low fluid, or the plugs, anyway, I'm sure glad it was not the tranny.