1970 800 80hp no spark

[ozarkjeep]

I just mounted this engine on my boat, I think it is wired correctly, key turns it over, with key on it has battery voltage at white and red lugs on switchbox.<br /><br />NO spark.<br /><br />coil primary tests at .3 ohm, secondary test at 368 ohms, its a rust colored round coil with a green and black wire coming out.<br /><br />replaced the timing belt, and the rotor brush in the distributer.<br /><br />How can I further check the coil, trigger, or switchbox?<br /><br />I want to replace the bad part, not all of them!

 

[emckelvy]

Re: 1970 800 80hp no spark

Here's a test you can do, courtesy of Clams (but I bet money on the distributor trigger being bad, it's usually the cause of a no-spark on these):<br /><br />"MERCURY BATTERY-POWERED CDI TEST <br />FOR DISTRIBUTOR MODELS<br /><br />This test is for the 332-2986 switchbox used from 1967-1978 on all the inlines.<br /><br />This test assumes your coil is good (most all are).<br /><br />DISCONNCT BATTERY <br /><br />1. Turn off ignion<br />2. Disconnect all 3 wires on the distributor side of the switchbox.<br />3. Remove the HV lead from the coil to the center cap (remember it unscrews<br />from cap)<br />4. Reconnect that HV center lead to the COIL side only.<br />5. Position that HV lead about about 3/8" from ground (block, shrouds etc)<br />and find a way to hold it there.<br />6. Jumber the brown and white terminals on the dist. side of the switchbox<br />together.<br /><br />RECONNECT BATTERRY<br /><br />7. Check that you have +12 V at red terminal.<br />8. Turn on ignition and verify +12V at white terminal (on red terminal side)<br />9. Touch the black terminal to ground - unit should cause spark each time<br />you touch ground.<br /><br />If that passes and it won't fire at all, suspect the trigger."<br /><br />HTH and Cheers...........ed

 

[ozarkjeep]

Re: 1970 800 80hp no spark

Thanks Ed,<br /><br />I have that test printed out right here, the problem is that doesnt narrow down the switchbox or coil.<br /><br />Is there some test for the trigger?

 

[rickdb1boat]

Re: 1970 800 80hp no spark

Using an ohmmeter, check the resistance between the side terminals of the coil. Do this with all of the wires to the coil disconnected. <br /><br />You should see 0.75 to 0.81 ohm of resistance. Then check the resistance between either side terminal and the center high tension terminal. The reading should be 10,000 to 11,000 ohms. Any significant deviation from these numbers would indicate that the coil is defective.