Spark Plug wire set for GM 2.5L 120 HP 153 cid and 3.0L 140 HP 181 cid engines used by Mercruiser and OMC. Used with the points ignition system with a conventional type Delco distributor.. Re: Spark plug wire order I found the firing order. It says 1-3-4-2, but what does that mean and will I hurt anything if I plug them in wrong?
Customer: which ways spark wire goes on mercruiser 3.0 Mechanic's Assistant: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Electronics Specialist I'm going to connect you with knows all the tricks and shortcuts.. Re: Mercruiser 3.0 Liter Firing Order first get a engine whistle take out the spark plug and screw the whistle in when the whistle sounds you are on the comnpression stroke. Go from there 4 cyl engines are either 1342 or 1432.