Has anyone in the group had experience with a rattling BMW MKII sterndrive
unit or an early Volvo which is similar. Mine rattles loudly after a run on
the plane when you come down to idle speed. It wont rattle in neutral till
you get the revs up to about 1800 then the rattle comes back.

It has no decernable rattle under load, just idle after a planing run. The
unis and gimbal bearing have already been replaced. When I dont use the boat
a few days and start up it is quiet at first, but always comes back.

Anyone?

Thanks
Cam

"Grant" wrote in message
...
Has anyone in the group had experience with a rattling BMW MKII sterndrive
unit or an early Volvo which is similar. Mine rattles loudly after a run
on the plane when you come down to idle speed. It wont rattle in neutral
till you get the revs up to about 1800 then the rattle comes back.

It has no decernable rattle under load, just idle after a planing run. The
unis and gimbal bearing have already been replaced. When I dont use the
boat a few days and start up it is quiet at first, but always comes back.

Anyone?

Thanks
Cam

A flex plate can do that. Might be worth checking.

Dan

On Feb 19, 9:32 pm, "Danlw" wrote:
"Grant" wrote in message

...

Has anyone in the group had experience with a rattling BMW MKII sterndrive
unit or an early Volvo which is similar. Mine rattles loudly after a run
on the plane when you come down to idle speed. It wont rattle in neutral
till you get the revs up to about 1800 then the rattle comes back.

It has no decernable rattle under load, just idle after a planing run. The
unis and gimbal bearing have already been replaced. When I dont use the
boat a few days and start up it is quiet at first, but always comes back.

Anyone?

Thanks
Cam

A flex plate can do that. Might be worth checking.

Dan

I was thinking the same thing, But I wonder if the engine actually has
a flex plate (like an automatic trans) or if the ring gear or is
pressed on the flywheel (like a manual shift)?

Most marinized engines use a regular flywheel. A flexplate is typically
used with an automatic trnsmission and in that case the torque converter
acts as the flywheel weight.

"Tim" wrote in message
ups.com...
On Feb 19, 9:32 pm, "Danlw" wrote:
"Grant" wrote in message

...

Has anyone in the group had experience with a rattling BMW MKII
sterndrive
unit or an early Volvo which is similar. Mine rattles loudly after a
run
on the plane when you come down to idle speed. It wont rattle in
neutral
till you get the revs up to about 1800 then the rattle comes back.

It has no decernable rattle under load, just idle after a planing run.
The
unis and gimbal bearing have already been replaced. When I dont use the
boat a few days and start up it is quiet at first, but always comes
back.

Anyone?

Thanks
Cam

A flex plate can do that. Might be worth checking.

Dan

I was thinking the same thing, But I wonder if the engine actually has
a flex plate (like an automatic trans) or if the ring gear or is
pressed on the flywheel (like a manual shift)?

Stern drive boats do indeed have a flexible coupling between the engine
flywheel and the intermediate shaft which attaches to the universal joints.
In the BMW it is a flexplate with a spline. The Mercruisers have a rubber
coupling.

Cam

"James" wrote in message
nk.net...
Most marinized engines use a regular flywheel. A flexplate is typically
used with an automatic trnsmission and in that case the torque converter
acts as the flywheel weight.

"Tim" wrote in message
ups.com...
On Feb 19, 9:32 pm, "Danlw" wrote:
"Grant" wrote in message

...

Has anyone in the group had experience with a rattling BMW MKII
sterndrive
unit or an early Volvo which is similar. Mine rattles loudly after a
run
on the plane when you come down to idle speed. It wont rattle in
neutral
till you get the revs up to about 1800 then the rattle comes back.

It has no decernable rattle under load, just idle after a planing run.
The
unis and gimbal bearing have already been replaced. When I dont use
the
boat a few days and start up it is quiet at first, but always comes
back.

Anyone?

Thanks
Cam

A flex plate can do that. Might be worth checking.

Dan

I was thinking the same thing, But I wonder if the engine actually has
a flex plate (like an automatic trans) or if the ring gear or is
pressed on the flywheel (like a manual shift)?

"Grant" wrote in message
...
Stern drive boats do indeed have a flexible coupling between the engine
flywheel and the intermediate shaft which attaches to the universal
joints.
In the BMW it is a flexplate with a spline. The Mercruisers have a rubber
coupling.

Cam


And, I have seen them with slots instead of holes due to wear. Thing is, if
you can hear it in the boat, that is usually where the problem is, though
can be upper gear case
as well.

Dan