454 mercruiser when running or idling it's getting gas in exhaust behind
boat
changed carburetor and still the same. Any comments will be appreciated

On Sat, 21 May 2005 18:17:02 -0400, "richard"
wrote:

454 mercruiser when running or idling it's getting gas in exhaust behind
boat
changed carburetor and still the same. Any comments will be appreciated


One or more cylinders not firing, possibly?

Brian Whatcott Altus OK

Brian, are you sure it's gas? The reason I ask is because a sheen in
the water is frequently caused by a leak in a transmission, or engine,
oil cooler. All it takes is a pin hole in the cooler. Keep an eye on
the transmission fluid and engine oil level, if you have a cooler for
each, or a combination cooler, if the level is dropping very slowly
(only when engine is running) remove the cooler and have it pressure
checked. If that's not it how is the engine temp.? Is it a little too
cool. A cold running engine tends to not burn all the fuel, leaves a
sheen in the water. As Brian indicated, you could have a cylinder not
firing. That's easy to check, with the engine running at idle, with a
pair of pliers, pull the end of the wires out of the distributer cap
one at a time. If the engine runs rough when a wire is lifted up, or
the RPM's drop, that cylinder is firing, if their is no change, that
cylinder is bad.