1987 3.0 omc

[Chip parman]

Everything I have read on the plug wire p lament say the firing order is 1-3-4-2 my boat is wired 4-2-3-1 when I change the wires to the correct way it won't start and it popped threw the exhaust can anyone help thanks in advance

 

[inthedirtagain]

Sounds to me like its timed off the wrong cylinder, or the timing is off a tooth. Only way to confirm is to pull the timing cover and make sure that your marks are lined up when the #1 (cylinder closest to helm) is at TDC and the distributor is pointing to #1. You can time an engine off of any cylinder, but all shop references will be off if not timed to #1.

 

[bruceb58]

Firing order is 1-3-4-2.

Cylinder #1 is the one closest to the BOW of the boat.

It actually starts and runs with the way you think it should be? What is the history of this engine? Have you ever had it running?

Is the rotor of the distributor cap pointing to #1 wire when the engine is at TDC on the compression stroke?

 

[Chip parman]

Yes boat runs on 4-2-3-1 will nor run the other way I just got the boat and they put an ignitor in it and took out the points . I put a new alternator in and took it out then was going across the lake at 3/4 throttle then I heard a rattle in the back and slowed down now I can get it to plane out. Changed the cap rotor plugs and wires cleaned both the fuel filters and it is like it is still starved for gas. If it cranks hard it will fire and run for a little bit then die. If it cranks easy it never starts .

 

[bruceb58]

Since pistons 1 and 4 are at TDC at the same time, its basically impossible to have that firing order. If you were running with some strange firing order, hopefully you didn't blow a hole in a piston. The firing order you were using is actually almost correct except you have 1 and 3 swapped.

Did you use a timing light to set timing?

 

[Maclin]

The wires in order on the cap can be 1-3-4-2 or 3-4-2-1 or 4-2-1-3 all that matters is the sequence. Try switching 1 and 3 on your "4-2-3-1" sequence.