Engine Shut-Off Problem - Mercruiser 3.0L (2003)
 

I know this is a common problem but am still at a loss to eliminate.
Motor continues to try to run when it is shut off, which is likely a
timing issue. Can I simply unbolt the distributor cap and rotate it?
Did not look like that was possible. Any suggestions- other than
higher ocatane fuel?

bigtwinhog

Engine Shut-Off Problem - Mercruiser 3.0L (2003)
 

"bigtwinhog" wrote in message
ups.com...
I know this is a common problem but am still at a loss to eliminate.
Motor continues to try to run when it is shut off, which is likely a
timing issue. Can I simply unbolt the distributor cap and rotate it?
Did not look like that was possible. Any suggestions- other than
higher ocatane fuel?

bigtwinhog

I don't think you should do that. I think you should hire someone to check
the timing for you. Check idle speed too. Engine might be running too hot or
too rich, carboning up etc.

Engine Shut-Off Problem - Mercruiser 3.0L (2003)
 

Yes, on a newer unit, you should not just change timing. To check timing
requires a shunt to be used. Things that cause overrun on these are...
shutting the engine down right after a high speed run, an engine running to
rich, adjust carb, high idle speed, and most important an engine that is
running hot.


"Jim" wrote in message
nk.net...

"bigtwinhog" wrote in message
ups.com...
I know this is a common problem but am still at a loss to eliminate.
Motor continues to try to run when it is shut off, which is likely a
timing issue. Can I simply unbolt the distributor cap and rotate it?
Did not look like that was possible. Any suggestions- other than
higher ocatane fuel?

bigtwinhog

I don't think you should do that. I think you should hire someone to check
the timing for you. Check idle speed too. Engine might be running too hot
or
too rich, carboning up etc.

Engine Shut-Off Problem - Mercruiser 3.0L (2003)
 

There was a bulletin on that, to try to idle for a while before shutting
down. I will try to look it up to see if it gives any other suggestions.


"bigtwinhog" wrote in message
ups.com...
Thanks much, I was afraid of that. Idle is actually pretty close and
problem is generally associated with shutting down after high speed
run.




Ron Knapik wrote:
Yes, on a newer unit, you should not just change timing. To check timing
requires a shunt to be used. Things that cause overrun on these are...
shutting the engine down right after a high speed run, an engine running
to
rich, adjust carb, high idle speed, and most important an engine that is
running hot.


"Jim" wrote in message
nk.net...

"bigtwinhog" wrote in message
ups.com...
I know this is a common problem but am still at a loss to eliminate.
Motor continues to try to run when it is shut off, which is likely a
timing issue. Can I simply unbolt the distributor cap and rotate it?
Did not look like that was possible. Any suggestions- other than
higher ocatane fuel?

bigtwinhog

I don't think you should do that. I think you should hire someone to
check
the timing for you. Check idle speed too. Engine might be running too
hot
or
too rich, carboning up etc.

Engine Shut-Off Problem - Mercruiser 3.0L (2003)
 

This run on is usually a combination of things. Here is a list of what has
to be done. 1,2,and 3 must be correct and need to be checked. The rest are
additional to help eliminate.

1. Be sure engine idle mixture, idle rpm and ignition timing are correct. On
4 cylinder and V6 or V8 engines
with Thunderbolt IV ignition, setting idle rpm as low as possible can help
stop 'run on'.
2. Adjust throttle cable barrel so that the carburetor's throttle lever
returns against the idle speed stop
screw every time the remote control throttle lever is returned to neutral,
idle.
3. Idle engine 1 to 1-1/2 minutes before turning key off after running at
cruise or higher engine rpm.
4. Try a different brand of regular fuel or try some premium fuel.
5. Increase idle mixture by 1/8 turn 'richer'.
6. Go to next colder heat range spark plugs.

Also, a slightly worn water pump can cause the engine to run 15 degrees or
so hotter. While this may normally be ok, this difference in engine temp
can contribute to the problem.


"Ron Knapik" wrote in message
...
There was a bulletin on that, to try to idle for a while before shutting
down. I will try to look it up to see if it gives any other suggestions.


"bigtwinhog" wrote in message
ups.com...
Thanks much, I was afraid of that. Idle is actually pretty close and
problem is generally associated with shutting down after high speed
run.




Ron Knapik wrote:
Yes, on a newer unit, you should not just change timing. To check
timing
requires a shunt to be used. Things that cause overrun on these are...
shutting the engine down right after a high speed run, an engine
running
to
rich, adjust carb, high idle speed, and most important an engine that
is
running hot.


"Jim" wrote in message
nk.net...

"bigtwinhog" wrote in message
ups.com...
I know this is a common problem but am still at a loss to eliminate.
Motor continues to try to run when it is shut off, which is likely
a
timing issue. Can I simply unbolt the distributor cap and rotate
it?
Did not look like that was possible. Any suggestions- other than
higher ocatane fuel?

bigtwinhog

I don't think you should do that. I think you should hire someone to
check
the timing for you. Check idle speed too. Engine might be running too
hot
or
too rich, carboning up etc.