engine cranking but not turning over

[stock333]

engine is 5.0 engine cranks but not starting what suggestion that i should look at to determine what might be the problem.

Appreciate your help

Thanks

Mark

[mmwjr]

First verify run/ kill switch is in run position. Next see what voltage is on the + terminal of the ignition coil. Have you checked for spark and fuel?

[stock333]

Thanks Admiral for your reply.

Went to boat today and it started Wires or something must have been wet.

Just curious in order to check the coil in the future. do i need to disconnect the 2 wire on the coil and if not can i test it with the battery terminals still connected to battery with the battery switch on or off.

Thanks

Mark

[mmwjr]

Originally Posted by stock333

Thanks Admiral for your reply.

Went to boat today and it started Wires or something must have been wet.

Just curious in order to check the coil in the future. do i need to disconnect the 2 wire on the coil and if not can i test it with the battery terminals still connected to battery with the battery switch on or off.

Thanks

Mark

To test for power at the coil leave everything connected, battery switch on and ignition switch in the run position. Place the positive lead of the voltmeter on the + terminal of the coil and the negative lead of the voltmeter to a good negative such as the battery. Note the - terminal on the coil is not ground but pulses around +2V to +8V.

[jrsick]

There is excellent troubleshooting info in your mercruiser manual (#24), see pages 1C-8 and 1C-9 (Engine Cranks but Will Not Start). The manual provides great info to help fix problems and understand systems.