wrote in message
...
On Mon, 31 Jan 2005 21:34:57 -0600, "del cecchi" wrote:
apparently 2 stroke inline 4s have issues leading to
bizarre solutions like the 2+2 on my Merc.

What sort of issues?
I've wondered for a long time why anyone would intentionally design an
engine that doesn't run on all cylinders. The only 2+2 I've had
personal experience with (115 Merc) would shake/vibrate the whole boat
at low rpms. A trip to the shop would temporarilly fix the problem but
second or third time out, the shake/vibration problem would return.

Anybody know the point of intentionally running on only two out of
four cylinders?
Related question, how do the non-firing cylinders receive lubrication
without pumping raw fuel/oil out the exhaust at low rpms?

Just wondering.........
Thanks
Rick

Be aware that some models of Yamaha V6 outboards, both EFI and HPDI, shut
down 2 or 3 cylinders at idle and low speeds.

Bill Grannis
service manager