All Cylinders Working?

[keeper]

Hi Guys!

Newbie Question Here. How Do I Know If All 6 Cyl Are Working. Tomorrow I Am Going To Get A Spark Tester, Will That Tell Me? I Am A Machinist, I Wish I Was A Mechanic

Thanks

Mark

[sosmerc]

The engine needs to be under a load, then pull the spark plug leads off one at a time. The engine rpm will drop noticeably when you pull the lead off. Add a ground wire with an alligator clip to your pliers so that you can ground your pliers to the engine...this will prevent you from getting a shock. Again, the engine must be in gear and under a load during this test. You can do this with the boat on the trailer, backed into the water.

[dynobo]

EASIEST way for me is to take a buddy with you and back the boat just far enough in to cover the Ventilation plate. Use a regular timing light and connect to each plug wire individually while trying to accelerate. If the spark is not constant on each cylinder then you have a problem on the affected cylinder. If all cylinders are sparking at WOT you may have a timing issue or fuel related problem.

[dynobo]

HARD to diagnose without on the water testing unless you have proper tools. A peak reading meter or DVA is necessary to check for individual component testing. Read this board and learn what you can between now and spring and you will be able to diagnose that old Merc in no time.