Engine / transmission problem

[Weasel]

Hey Guys & Ladies,

Beneteau 331, Yanmar 3GM30F
Transmission, Kanzaki KMZP-1
(Integral throttle / shifter

After a great day on the water here in TN with some actual wind in Aug I encountered a problem with backing into my slip (and this may have been my fault). I had put the engine in reverse from forward to back up, and it felt like the engine was coming off it’s mounts and out the engine compartment. I may have been shifting to fast, ie: not stopping at neutral.
Always check oil in X-mission as part of my pre-checks, also check engine mounts, and oil, filters etc on engine. Engine has 354 hours on it, boat is a 2004 model, which I purchased new. Also it shook in neutral, again like I said, I may have have been shifting to fast. (Lots of traffic and had to back in slip) . Any ideas? I’m going to try running this through the gears slowly again in the slip and see what happens. Appreciate comments!

Thanks

 

[mcrow33]

Is it possible that you picked up weeds? I back my 361 into my slip and earlier in the summer I had a lot of weeds floating in the fairway and in the slip. When I backed through them, I picked up a lot on my rudder and prop shaft. The engine started vibrating a lot and bogged down. I had to give the engine more throttle in reverse to get into the slip. Luckily the marina clean up the weeds.

 

[Benny17441]

That is likely the prop biting into the water in a direction opposite to the movement of the boat. If the problem persists then you could have picked up something, weeds or an ice bag. Your boat is 13 years old and motor mounts have been known to fail as early as 7-10 years of use so it would not hurt to inspect them for softness or cracks. A visual inspection is unreliable as the rubber will usually look good but could be shot. I use a pry bar to lift the engine and stretch the mounts. A broken mount will allow the engine to lift right off and a soft one will not offer much resistance. I recommend checking them because you reported the engine shake in neutral.

 

[Ilanortho]

Did the killer seaweed also; engine lost power, black smoke but not the horrible intermittent banging that the slipping clutch caused.

 

[markwbird]

I have been dealing with a similar issue with some differences in the details. My boat shakes like that but only in forward. What I’ve read is that the drive cone in that tranny can “hammer” when it slips. In your case there are many other possibilities based on your description but this could be one.

 

[Ilanortho]

"Hammer" is the best description to what I experienced. Was frustrating in that it was frequently intermittent but once it started would do so for many minutes and sound horrible.

 

[JimInPB]

If you have a drive cone problem, you will usually see a metallic shimmer in the tranny oil.

I would look for a bent shaft, a bad bearing or a broken mount if nothing is wrong with the prop.

 

[odaydokay]

I would pop into the water with a mask and have a look . Give the prop a strong lateral wiggle right and left as a shot cutlass bearing is another possibility.