1985 merc 75 hp 4 cyl. Will not start.

[Coltrickle]

I purchased a 1985 Dixie ski boat last fall.. The engine ran flawless.. After I got home and started looking I noticed a trigger wire very brittle and on two strands of wire holding it together.. I opted to replace the trigger.. Now it won't start.. I am getting spark to all cylinders but it will not start... Any ideas?? Thanks

 

[CharlieB]

Re: 1985 merc 75 hp 4 cyl. Will not start.

Double check the color codes on the switchbox to see that the trigger wires are connected to the correct terminals, otherwise the ignition firing order will be skewed.

It is rare, but, a trigger can be assembled with the wires incorrect and skew the firing order.

Remove the spark plugs, turn the motor until a piston is at TDC and mark the flywheel at the timing pointer with that piston #, repeat for each cyl. Use a timing light and check cranking each plug wire should make the light flash so you can see you # near the timing mark. Check each plug wire. If you see any other # other than the wire you are on then the trigger is either defective or you have the trigger wires incorrect.

 

[Coltrickle]

Re: 1985 merc 75 hp 4 cyl. Will not start.

Thanks charlieb I have checked the wiring and all seems to be correct.. I have since got the engine started once and then went dead.. After about 5 seconds.. I have put my battery on charge after reading that a battery not near full charge will be enough to crank but not start and run the engine.. I will also track down a timing light and make sure my new trigger is wired correctly.. Thanks again..