Re: Mercruiser - drastic drop in Idle in gear
If you have a timing light, you can check that out. At least if it's an ignition issue. Put the timing light on any plug wire. If it flashes, the sparkplug is sparking.<br /><br />I learned this little trick last year from my former employer and it works like a dream. If you take a 12v circuit tester (pointy thing that looks like a screwdriver with a light bulb in it and a wire with an alligator to ground it), slide it in where the plug wire goes into the sparkplug boot. Slide it in far enough and it sparks there instead of the sparkplug (the light won't light). If the cylinder is contributing to the power, you'll notice a significant drop in RPMs. If the drop is slight or unnoticable, there's a problem with that cylinder. (Same thing as if you pull plug wires, but I got zapped too many times. Even with plastic pliers. Never got zapped with this method. I thought for sure it would blow the bulb to kingdom come, but it doesn't. Still using the same tester with the same bulb on trailer lights or whatever.)
