Wayne,
There are many different types.Some are rubber some are spring dampened,
like clutch plates. Others are just a splined hub with spring steel wings
that bolt at a large bolt circle. It is easy to disconnect the generator
from the engine, if it no longer is in the boat. The difficulty in the boat
is limited to the ease of access. On a shop floor, 15 minutes has the engine
and generator separated.
Steve

"Wayne.B" wrote in message
...
On Sun, 5 Sep 2004 09:49:03 +0200, "Steve Lusardi"
wrote:
My guess is that it is not electrical. I think your flex plate drive is
either loose or worn out. The alternator has bearings only on the outboard
end. The engine rear main bearing acts as the other armature bearing. This
mechanical connection is usually done through a flex plate which is bolted
to the engine flywheel and a splined hub drives the armature or rotor. To
check this, the alternator must be removed from the engine.

===============================================

Thanks, your assessment of not being electrical jibes with my
observations. What would explain the intermittent nature of the
vibration given a more or less constant electrical load? Is the flex
plate a coupling with a rubber hub?

On Mon, 6 Sep 2004 21:00:43 +0200, "Steve Lusardi"
wrote:

On a shop floor, 15 minutes has the engine
and generator separated.

Thanks, mine is in a fairly accessible location.

I'd try to divide some possibilities, hoping to conquer:

-- Determine if it's a loading or engine malfunction thing by very
carefully marking the governed throttle/injection pump actuator position
under 'normal' operation. If this suddenly moves under the fault
condition, the engine is getting more fuel then. If it doesn't then it's
not load or engine power related, and it's a looseness / shifting
mechanical thing. Maybe coupling, or worse, a loose flywheel.

-- IF it's an 'increased load' thing, two possibilities: (1) Sudden
added load as mentioned by others. Is There an ammeter on this rig??
(2) Sudden intermittent engine malfunction on one cylinder. Sticking
valve? Sticking Injector?

I'd bet on #2 as it would cause strong vibration due to uneven firing.

Keep eliminating 1/2 the possibilities and you'll find it....

--
Regards, Terry King ...On the Mediterranean in Carthage