Low RPMs and a 4 stroke
 

Am I hurting my 60 EFI merc 4s by running at 1200-1500 RPM? I know that is
tough on a 2s. (fouled plugs, shaky lubrication etc)
I have about 35psi oil pressure, water running at the stat temp, 6-8 PSI water
pressure, computer seems to be metering gas OK and the battery is charging.
What else should I be worried about?

I beleive it will carbonize as it doesnt get hot enough ... Why not get
a kicker?

Matt

I beleive it will carbonize as it doesnt get hot enough ...

Why not get
a kicker?


Ah the old, we gotta go "blow the carbon out" thing. I think the EFI computer
is better at metering gas than my Dad's Desoto. It is running at the stat.


There are lots of reasons I don't want a kicker.

Any other things?

You should have no problem. EFI will do its job and unlike a 2 stroke - the
oiling should be fine. And as you said, the temp is right.
Think about how long a car engine runs at 1500 rpms on a long trip (at least
my truck runs at 1500 at 63 mph for a long time going to my parents which is
all 2 lane roads).

Tony

"Greg" wrote in message
...
Am I hurting my 60 EFI merc 4s by running at 1200-1500 RPM? I know that is
tough on a 2s. (fouled plugs, shaky lubrication etc)
I have about 35psi oil pressure, water running at the stat temp, 6-8 PSI
water
pressure, computer seems to be metering gas OK and the battery is
charging.
What else should I be worried about?

Thanks Tony That is my thinking. I was just hoping Bill or one of the other
service guys would confirm that. I am coming up on 1000 hours on my 2002 and I
would like to see a couple thousand more.

I put almost 3000 on my 75 Mariner.

"Greg" wrote in message
...
Am I hurting my 60 EFI merc 4s by running at 1200-1500 RPM? I know that is
tough on a 2s. (fouled plugs, shaky lubrication etc)
I have about 35psi oil pressure, water running at the stat temp, 6-8 PSI
water
pressure, computer seems to be metering gas OK and the battery is
charging.
What else should I be worried about?

That sounds about right. But if you are in doubt, call the Merc service
center in your area and they should confirm that this is acceptable for an
EFI 4-stroke.

If this were a 60 HP 2-stroke, and you were to run it at that RPM or lower
for a long period each time you went out, you could have problems. I pulled
apart an older 60 HP Merc 2-stroke about 2 years ago and the exhaust tube
was plugged almost completely, because the old fella used it for trolling
and never went close to WOT for more than 5 minutes each trip. The exhaust
chamber looked like it had been used on the top of a wood stove. I spent an
hour "mining" the carbon out of it.

Greg wrote:

Am I hurting my 60 EFI merc 4s by running at 1200-1500 RPM? I know that is
tough on a 2s. (fouled plugs, shaky lubrication etc)
I have about 35psi oil pressure, water running at the stat temp, 6-8 PSI water
pressure, computer seems to be metering gas OK and the battery is charging.
What else should I be worried about?


I have the same engine and do a lot of trolling at low RPM's- no
problems. I've heard talk about the motor "making oil" from condensation
under these conditions, but I haven't seen a problem.

On 01 Feb 2005 18:20:03 GMT, (Greg) wrote:

Am I hurting my 60 EFI merc 4s by running at 1200-1500 RPM? I know that is
tough on a 2s. (fouled plugs, shaky lubrication etc)

I had three of these on my sloop. You will not hurt the engines at all
running that way, as long as you dont let your generator exceed 92.5
kw.

I have about 35psi oil pressure, water running at the stat temp, 6-8 PSI water
pressure, computer seems to be metering gas OK and the battery is charging.
What else should I be worried about?

On those engines, you need to make sure the have plenty of draft. On a
short freeboard hull, you run the risk of over-heating.