After getting off a sandbar boat started going progressibely slower over time

tu1aher1

Seaman Apprentice
Joined
Jun 3, 2015
Messages
41
Hello all,

I have a 84 Hammond with a Mercruiser 140 3.0 Alpha One Gen One. I was out on the lake and got stuck on a sandbar. I raised the outdrive up and after turning the wheel back and forth going forward and reverse I finally got it out. I raised the outdrive pretty far but I was a ware of not raising it too far not to damage the u joint. My trim sender is not working but I never heard any problems when I raised it.

Anyway the boat seemed to run fine for about 5 min then I started losing power from the outdrive. Kind of like the engine puttering out but I could put it in neutral and the engine would run fine so I know it has to be the outdrive. It started getting worse until I could only run it at the speed you get when you first put it in forward gear which is pretty slow. But it would have no problem at this speed forward or reverse. If I tried to give it more gas the out drive acts like it starts losing power so I quickly bring it back to the speed you get when you first put it in gear. After a long time I finally got it back to the dock. Is this a bad prop hub? It progressively got worse and the engine runs like a champ.

The engine stays nice and cool the whole time so I don't think the outdrive is full of sand or mud. I did some tests on the trailer hooked up to the water hose. I can turn my outdrive all the way to port and starboard with no issues or noise from the u-joint. It goes in and out of forward and reverse fine and stays in gear. The prop turns on land fine both forward and backwards and is easy to turn by hand in neutral. Of course there is no load on it sitting on the trailer. Did I loose my prop hub? Any help on what it could be would be very much appreciated.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,947
Hello all,

I have a 84 Hammond with a Mercruiser 140 3.0 Alpha One Gen One. I was out on the lake and got stuck on a sandbar. I raised the outdrive up and after turning the wheel back and forth going forward and reverse I finally got it out. I raised the outdrive pretty far but I was a ware of not raising it too far not to damage the u joint. My trim sender is not working but I never heard any problems when I raised it.

Anyway the boat seemed to run fine for about 5 min then I started losing power from the outdrive. Kind of like the engine puttering out but I could put it in neutral and the engine would run fine so I know it has to be the outdrive. It started getting worse until I could only run it at the speed you get when you first put it in forward gear which is pretty slow. But it would have no problem at this speed forward or reverse. If I tried to give it more gas the out drive acts like it starts losing power so I quickly bring it back to the speed you get when you first put it in gear. After a long time I finally got it back to the dock. Is this a bad prop hub? It progressively got worse and the engine runs like a champ.

The engine stays nice and cool the whole time so I don't think the outdrive is full of sand or mud. I did some tests on the trailer hooked up to the water hose. I can turn my outdrive all the way to port and starboard with no issues or noise from the u-joint. It goes in and out of forward and reverse fine and stays in gear. The prop turns on land fine both forward and backwards and is easy to turn by hand in neutral. Of course there is no load on it sitting on the trailer. Did I loose my prop hub? Any help on what it could be would be very much appreciated.

You either spun your prop hub or spun your engine coupler. My guess is that since you didn't smell burning rubber it's probably the prop hub. Take your prop off and look at the hub
 

fhhuber

Lieutenant
Joined
Jun 19, 2014
Messages
1,365
Mark the hub in such a way as to be able to see if the prop is spinning around the rubber insert (or the insert around the center splined part) Take it on the lake for a couple of minutes. Pull it out and look to see if there's any shift in the marks.

ANY shift is time to get the prop hub pressed out and a new rubber insert pressed in.

Found a pic (hope it lets the link work)

http://www.myfishingpictures.com/data/500/s7_019429_imageset_01.jpg
 
Last edited:

tu1aher1

Seaman Apprentice
Joined
Jun 3, 2015
Messages
41
Thanks for the reply. No I didn't smell any burning rubber at all and I didn't hear any metal grinding in any way. I will mark the prop as suggested and take the boat to the lake tomorrow and see what I find. I'll keep you informed.
 

superbenk

Commander
Joined
Oct 27, 2008
Messages
2,033
You're saying the engine RPMs actually start to drop after a bit though? As if the engine is lugging?
 
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