OMC 305 cranks but will not start Help!!!!!!!

[solar7647]

1987 OMC 305. Turn the key cranks, sound like it starts and as soon as you let go of the key it dies. But if I jump a wire from the alternator to the positive of the coil it starts and runs. So I changed the coil, still want start, checked alternator to see if bad, its good. Checked assist soleniod its good, Checked starter soleniod its good, changes ingnition switch its good. changed Condensor in distributor. Does any one have an idea? please.

 

[bruceb58]

Re: OMC 305 cranks but will not start Help!!!!!!!

The reason it starts while you are cranking is becuase the starter solenoid supplies the power but only during cranking. You need to trace back:

1) from the coil to the ballast resistor
2) from the ballast resistor to the engine harness.
3) from the engine harness to the safety lanyard switch
4) from the safety lanyard switch to the ignition switch

I am sure you will find a break in there somewhere.

Also make sure your safety lanyard is clipped on the safety switch

 

[solar7647]

Re: OMC 305 cranks but will not start Help!!!!!!!

As far as i can tell the resiter is good. It is in a ESA box so i cant test it streight foward but i get conection where i need it. There is no safty lanyard switch so thats not it. Maybe the interupter switch?

 

[seattle2855]

Re: OMC 305 cranks but will not start Help!!!!!!!

Make sure the laynard? (kill switch) is working.

 

[bruceb58]

Re: OMC 305 cranks but will not start Help!!!!!!!

The ballast resistor is not in an ESA box. The ESA is totally seperate unless you have something different than the 1987 OMC that I used to have!

I am surprised you don't have a safety switch. They were required back in 87.

 

[solar7647]

Re: OMC 305 cranks but will not start Help!!!!!!!

I have gone over it a few times and there is no kill switch in the cchematic or on the boat, so i dont think there is one. If the resistor is not in the ESA box then where is it. It is not in the schmatic ether?

 

[bruceb58]

Re: OMC 305 cranks but will not start Help!!!!!!!

Do you see anything that looks like this mounted on the intake manifold behind the carb?

Trace the wires going back from the coil positive terminal. One will go to the starter and the other will go to either a ballast resistor or possibly a resistor wire.

If you want to start out from the other end, start measuring voltages at the ignition switch and head the other way.

Just be glad this is a hard failure and not intermitant. it is not going to be that hard to figure out.