Timing a Mercury 1150 Hp Outboard Motor

Contributor

By Jillian Downer
eHow Contributing Writer

Article Rating:

(0 Ratings)

The power and acceleration for a motor boat is controlled by the timing belt and ignition timing. All motors have very specific measurements to establish appropriate timing, and these levels should always be adhered to. New boats should never need timing adjustments, but with use and over time, adjustments may need to be made to maintain the motor and to increase the lifetime of your boat. Adjusting the timing on a Mercury 1150 Hp Outboard Motor is simple if you have the appropriate tools. If you're experiencing problems when your boat's acceleration or you've lost power, you may need to adjust the timing; here's how to do it.

Difficulty: Moderate

Instructions

Things You'll Need:

Timing light
Spark plug gap tool

Step 1

Install your temporary spark gap tool. Remove the cowling cover from the power head and remove the spark plugs. Detach the throttle cable and attach the spark gap tool into the holes where the spark plugs were.
Step 2

Attach a timing light to the first lead. You must use a timing light in order to accurately adjust the timing.
Step 3

Adjust the idle timing. Shift into neutral and start the engine while holding the throttle arm. Adjust the idle timing screw so that it is 2 degrees before top dead center. Turn off the engine.
Step 4

Adjust the timing for throttle at wide open (WOT). Shift into "Neutral" and start the engine while holding the throttle arm. Adjust the maximum timing screw so that it is 28 degrees before top dead center. Turn off the engine.
Step 5

Replace the equipment. Remove the dial indicator and spark gap tool and replace the spark plugs. Place the cowling covering back on the power head.

Tips & Warnings

If adjusting the ignition timing does not fix the boat's power and acceleration issues, you may also need to adjust the belt timing. Some boats can last an entire lifetime without needing a timing adjustment, so do not make adjustments unless absolutely necessary.
Throttle at wide open should never be over 28 degrees before top dead center.

Who Can Help Sponsored