swampyankee
Contributing Member
Long story here, and looking for anything I might have missed in troubleshooting a no-start condition:
Last fall I purchased a nice-condition Slickcraft 279SC with carburetted 5.7L and Alpha One outddrive. The boat had not been on the water in 2021 because the PO could not get it started. He had 2 different techs look at the boat trying to diagnose the problem. One had cut the engine wiring connector out and butt-spliced wiring together because he thought one of the pin connectors was bad. Clearly not a very good tech. The boat checked off alot of boxes for us so I took a look. After turning it over, I hot-wired the ballast resistor and sprayed some gas in the carb and got it to fire. Feeling that the problem was in the wiring, and being a former electrician with alot of experience troubleshooting auto electrics, I bought the boat very cheaply.
After some troubleshooting and a new starter, I found a bad ground to the aftermarket Carter fuel pump which I corrected. The 3 pole oil pressure switch typically used in conjunction was badly rusted so I replaced that with a marine grade one, and wired things per the Carter manual. After that the engine started and ran fine. There were more wiring issues such as the tach sender wire being disconnected at the coil so I reconnected it and got the tach working.
Fast-forward to this past weekend when I was prepping the boat to launch - I couldn't get the engine to fire. Thinking the year-old gas might be bad, I sprayed fuel into the carb, but it still would not fire. I pulled a plug and initially got a weak spark (red, not white). I started re-checking my power connections to the coil, ignition, etc. I found a Mallory 609 module in the distributor that was loose so I secured it properly. I also verified power and ground to it, as well as power to the coil. Still no joy, and now no spark at a plug. I found a rats nest of hot connections tagged onto the hot wire going to the ballast resistor - ignition module, fuel pump power to the N.O terminal on the oil pressure switch (start circuit power goes to the N.C. terminal), and a mysterious purple wire that goes back into the engine harness (I'll trace that one out).
Verifying I have power to the ignition module and coil, I will check and adjust the gap at the ignition reluctor, but the next step would be to bench-test the coil and ignition module. Anything else I should look at? Anything I might have missed?
Last fall I purchased a nice-condition Slickcraft 279SC with carburetted 5.7L and Alpha One outddrive. The boat had not been on the water in 2021 because the PO could not get it started. He had 2 different techs look at the boat trying to diagnose the problem. One had cut the engine wiring connector out and butt-spliced wiring together because he thought one of the pin connectors was bad. Clearly not a very good tech. The boat checked off alot of boxes for us so I took a look. After turning it over, I hot-wired the ballast resistor and sprayed some gas in the carb and got it to fire. Feeling that the problem was in the wiring, and being a former electrician with alot of experience troubleshooting auto electrics, I bought the boat very cheaply.
After some troubleshooting and a new starter, I found a bad ground to the aftermarket Carter fuel pump which I corrected. The 3 pole oil pressure switch typically used in conjunction was badly rusted so I replaced that with a marine grade one, and wired things per the Carter manual. After that the engine started and ran fine. There were more wiring issues such as the tach sender wire being disconnected at the coil so I reconnected it and got the tach working.
Fast-forward to this past weekend when I was prepping the boat to launch - I couldn't get the engine to fire. Thinking the year-old gas might be bad, I sprayed fuel into the carb, but it still would not fire. I pulled a plug and initially got a weak spark (red, not white). I started re-checking my power connections to the coil, ignition, etc. I found a Mallory 609 module in the distributor that was loose so I secured it properly. I also verified power and ground to it, as well as power to the coil. Still no joy, and now no spark at a plug. I found a rats nest of hot connections tagged onto the hot wire going to the ballast resistor - ignition module, fuel pump power to the N.O terminal on the oil pressure switch (start circuit power goes to the N.C. terminal), and a mysterious purple wire that goes back into the engine harness (I'll trace that one out).
Verifying I have power to the ignition module and coil, I will check and adjust the gap at the ignition reluctor, but the next step would be to bench-test the coil and ignition module. Anything else I should look at? Anything I might have missed?
