1985 4 cyl not firing on two cyl.

[Steve Phillips]

This is a 4 cylinder 1985 50 hp. It fires and runs on cylinders 1&3 and does not fire on 2&4. Has new spark plugs. coils are on order. It had a bad rectifier which has been replaced but we have not tried to run it since. We are waiting for the new coils. Afraid we would destroy the new rectifier. What else could cause this problem.

 

[stork55]

You need to get an ohmeter and check resistance on the stator and trigger coils.Did you switch your leads around and see if 1&3 can make 2&4 fire,if they do that proves the ignition coils are good.If everything else checks ok then replace the switchbox.

 

[Steve Phillips]

What leads? Where

 

[stork55]

The leads from the switchbox to the ignition coils

 

[leachy]

you can also move the trigger wires on the switch box and see if the spark changes to the different plugs, but make sure you have the plugs out otherwise you will get a big miss-fire. this will check the trigger switch plate.