Thanks for that. I had no intention of trying to reset the timing, the
engine was intermittently idling rough (hunting), I was hoping to just
confirm there was HT going to the plug.- it couldn't be far off as the
engine would start OK from cold.
Steve

"BenC" wrote in message
om...
"Steve L" wrote in message
...
Yep, had exactly the same problem with a 4.3. Not being any sort of
expert
I spent days trying all sorts of things. I was about to check the
timing
advance with a old cheap neon strobe light I had knocking around, the
type
that plugs between the spark lead cap and the spark plug. I noticed the
flashes from the light were very erratic on all cylinders after the
engine
had warmed up. Cleaning and de-crudding the distributor and rotor arm
contacts resulted in strong regular flashes and a smooth running engine.
It
worked for me, but I don't quite know why.


typically, just putting a timing light on a v6 mercruiser wont give
you the correct timing. depending on the ignition system a base needs
to be set before the distributor can be set


Steve

"sudsy" wrote in message
om...
need help. my 1990 mercruiser 3.0L runs fine for the first 1/2 hour
or so. then after it sits while we swim or change skiers it starts
and revs fine, but runs very rough and even stalls when put into gear
and given gas. Not a fuel or fuel system problem since it always runs
good for the 1/2 hour or so. this problem is driving me crazy. any
suggestions welcome.

do you have a water separator? if not get one. it could be water in
your gas.
also get your ignition system checked, including your coil.