Mercruiser 3.0 Liter Firing Order

[steve464us]

I have a 2004 Mercruiser 3.0, 4 cylinder. I put my boat in the water for the first time since last year, and it was running very poorly. I think I may have crossed 2 sparkplug wires when I winterized last fall, or possibly have a fouled plug. Can anyone help me with the firing order on this engine?

 

[andy6.3]

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. I would think the fireing order is 1342 thry that first. also check the restistance of the HT leads Worn HT leads do not help with engine running

 

[Don S]

Re: Mercruiser 3.0 Liter Firing Order

IF the distributor hasn't been removed it will be like this.

Did you do a tuneup before launching?

 

[enn858]

Re: Mercruiser 3.0 Liter Firing Order

Firing order is as already stated 1-3-4-2 and cyl 4 is closest to flywheel.

All 4 cyl engines have cyl 4 closest to flywheel - except most Frensch (Peugeot Citroen etc.) engines - they have cyl 1 closest - guess how I found out

 

[steve464us]

Re: Mercruiser 3.0 Liter Firing Order

Thank you!

I did have the wires for 3 and 4 crossed. It's running well now.