28 Power boat Motor Mounts

[John Edwards]

Hi all:

Just back from a nice 4 days at the vineyard and have a question for ya all:

Buzzard's Bay had a steep chop today, perhaps 5-6 feet, to the point I slowed down to 5 knots for a while.

Often times when slaming about, the boat felt like she was wiggiling a bit, as tho the motor mounts are loose/shot. Wiggiling down aft is the best way I can describe it. Although I think the prop came out a few times, perhaps this caused the wiggle?

It kinda felt like my Cal 33 when the transmission was going bad...

Once the water smoothed out, I felt no more wiggiling, it was only when I was smashing about in the troughs...

I should addd that I have the Volvo 200 w/ the 4msa tranny (the one with the bad rep)

Gotta say that I love this boat and am having a great time with her, the 2 yrs of doing her over was well spent!

I'll see if I can post a few pics.

Thanks in advance

John Edwards
1988 CD 28 FB
#164
"NEO"

[Bill - Dulcie]

John,

First thing I'd check is the cutlass bearing.

Next I'd check the tightness of the motor mount nuts.

Then check for any shaft wobble - can do at pier in gear.

If all of the above check out OK, chances are your problem was cavitation in the chop. Weather sounds like the Chesapeake!

[John Edwards]

Thanks Bill:

There's no wobble in the shaft, but I will mention the other points to the yard who I hope will take a look at it.

I take it you haven't had an issue w your mounts?

It would seem that they should be due, as she's an 88.

John

[Bill - Dulcie]

John,

The only issue I've had with the engine mounts is loose nuts, and that happened after my cutlass bearing failed, resulting in some wobble in the shaft and consequent vibration of the engine at cruise. I tightened the nuts and replaced the cutlass bearing. The new bearing failed within a year, and my yard man and I decided that it was so watertight it was not getting sufficient lubrication. Tapped into cooling water hose immediately aft of the heat exchanger and ran a 1/4" hose to a hole I drilled in the shaft log just aft of the stuffing box. New cutlass bearing has now functioned for 10 years without problem, and mounting nuts have stayed tight.

That 1 1/2' SS shaft is probably over-engineered for the boat. Very difficult to bend. Running at about 3200 RPM, I hit a submerged cargo container (with the prop only) in the Baltimore shipping channel on the Chesapeake. Broke off a blade. Limped home at idle. Yard man insisted the shaft was bound to have been bent by the impact, so we dismounted it and had a machine shop check it. Shop reported back that shaft was still true to within 1/100th" for entire length! No wobble is detectable at any running speed.

Again, if I had a problem, I'd look elsewhere first. With an '88 boat, if there had been an engine mount/alignment problem, it would have manifest itself in some manner long ere this! Check the whole line from engine to prop, including such things as tightness of shaft coupling bolts/nuts, prop balance, etc. Let me know the outcome. Good luck!

[John Edwards]

Thanks Bill, I'm going to do these basic checks before I have the mechanics down.

This boat was on the hard for 9 yrs when I bought her, then I took 2 yrs doing her "make-over".

I'm starting ti think it was cavitation, cuz once the seas were down she was fine.

Have you ever expereinced cavitation?

John

[Bill - Dulcie]

John,

I suspect you have a whole set of problems about which I know nothing. Nine years on the hard! Seems almost criminal. I suspect things like seals, belts, hoses and gaskets would be troublesome. Again, good luck!

[John Edwards]

None yet.

The ole boy started her up at least once a year I'm told

We changed all the hoses, funny copper tubing seals/rings, all fluids cleaned out the heat exchanger (which was really clean) adjusted the valves, installed a new hot water heater, all new hoses for fuel & water, new steering helms & ram (they were frozen solid)

I'm hoping to get a whole bunch of pics of Ned's www.Capedory28.info site

Thanks

John