Mariner 40hp outboard problem

[Stephen Colley]

To all the outboard pros,

The Setup:

I have the following problem with a brand new, 1996, Mariner 40 hp
outboard. This is a 4 cylinder, oil injected unit with the "ELPTO"
configuration. The engine is installed on a new, 17 foot, aluminum,
"family fishing boat" which gets about 28 mph at full throttle and
about 5300 RPM. Operation is at an altitude of between 4300 and 6900
feet here in lofty New Mexico, USA. Fuel is brand name, medium
octane unleaded with no alcohol additive. Oil reservoir is full.

The Problem:

After launching and running a short time at low RPM, the problem
shows up after only a minute or two of running at full throttle.
RPMs start to decrease slowly say from 5300 to 4800 RPM or lower.
Then, after easing off to idle, the engine will not go above 2000
RPM without cutting out. The engine can be re-started with no
problems and runs below 2000 RPM but will die as RPMs go above 2000.

Findings:

The fuel squeeze bulb from the built-in tank is firm. Running with
a portable tank and completely bypassing the boats fuel tank makes
no difference. Complete engine replacement made no difference. The
original, new engine was replaced when the problem could not be
solved by the local dealer. The second, new engine shows the exact
same problem. For the short time of operation at full throttle
the engine runs smooth.

The dealer seems to have an experienced Mercury shop and continues
to put considerable effort towards the problem. Consultations with
Mercury have not helped.

Anyone seen this type of problem? Any suggestions?

--
Stephen Colley
Access Dynamics, Inc.
phone: 505-345-7637
fax: 505-345-7831
e-mail: col...@accdyn.com
WWW: http://www.accdyn.com/

[Harry Krause]

Try checking out the ignition switch. See if the switch is faulty
and actuating the electrical choke warm up switch intermittently.


Harry Krause hkr...@gate.net
P.O. Box 7575 Jacksonville, Florida 32238
- - - - - - - - - - - - - - - - - - - -
The wise open their minds, but a fool opens his mouth.

[abp...@ibm.net]

I had a simular problem with a 25 hp Johnson. The whine of the motor
would change after a few minutes. I found that by slightly pulling out the choke
out about 1/8 of an inch kept this from happening.

Good luck.
ROS

[C. A. La Varre]

abpitg wrote:
>>Anyone seen this type of problem? Any suggestions?

We have exactly the same problem on the same engine, but never found a
solution...

Andy La Varre
**Presented by Galahad**
http://www.alteng.com
Boat for sale: http://www.alteng.com/marine/newday/warrior.htm