i am the proud new owner of a 1983 Mako with V-135 Merc Black Max. I had it surveyed and the important items checked out OK...boat was relatively dry and solid, compression 128-130 on all 6, lower unit clean, merc ran good on land and in the water. the major issue noted by the surveyor was that i had no output for charging the batteries. i figured it was a bad rectifier which would be no big deal to replace.
fast forward two weeks, i have been running the boat in the driveway every night after work just to test it. it usually needs some quik start and lots of throttle to start (carbs get totally flooded) but otherwise works great and ran smooth (once it was running) for a '86 2 stroke. i make the mistake of planning a fishing trip saturday morning and get out there about 7 am to start it in the driveway before i head to the launch. first attempt with quik start doesnt work, no go on second and third. crank it a fourth time and the starter doesnt jump. just makes a electric fizzle sound. so we go fishing on my friends boat.
when i get home i jump from the positive terminal to the starter and it fires just like normal. so i started an electrical overhaul. the engine is now hooked up with CLEAN connections to a new starting battery. i try to start it monday night and starter works fine, cranks like champ, but wont start. i checked and had no spark on all cylinders.
i have tested the kill circuit by disconnecting mercury switch and disconnecting blk/yel to switch boxes, tested the neutral interlock switch, tested rectifier (which is visibly blown out see pic) by removing yellow wires, also disconnected entire wire harness and jumped the starter. still no spark. the red/white wire from my idle stabilizer was burnt/corroded so i cut out the bad section and replaced with new wire (this was burnt and corroded before i lost spark--see pic). checked resistances with below results...seems fine to me. i havent replaced the spark plugs yet cause i cant believe that all of them could be fouled at once/all of a sudden. nor have i checked the ignition coils because my wire colors didnt match the manual and i dont see how all could fail at once.
STATOR
blue/white to red/white = 6.47 kO (supposed to be max of 6.2...)
red/white to ground = 150 O
blue to red = 6.29 kO (supposed to be max of 6.2)
red to ground = 138 O
TRIGGER
black to ground = 0.00
brown to white (yellow sleeve) = 1.3 kO
white to violet (yel) = 1.299 kO
violet to brown (yel) = 1.302 kO
any other ideas? is 6.47 kO when its supposed to be 4.5 - 6.2 OK? could that explain why the rectifier crapped out in the first place?
please start with simple solutions first...based on my testing i think it has to be something simple...something i am overlooking. i thought the rectifier is just involved with the charging circuit, can it prevent the spark? i have another ignition switch...should i try putting that in?
thank you for the help. see pics here: http://picasaweb.google.com/leallyn.murtagh/Mako?feat=directlink
fast forward two weeks, i have been running the boat in the driveway every night after work just to test it. it usually needs some quik start and lots of throttle to start (carbs get totally flooded) but otherwise works great and ran smooth (once it was running) for a '86 2 stroke. i make the mistake of planning a fishing trip saturday morning and get out there about 7 am to start it in the driveway before i head to the launch. first attempt with quik start doesnt work, no go on second and third. crank it a fourth time and the starter doesnt jump. just makes a electric fizzle sound. so we go fishing on my friends boat.
when i get home i jump from the positive terminal to the starter and it fires just like normal. so i started an electrical overhaul. the engine is now hooked up with CLEAN connections to a new starting battery. i try to start it monday night and starter works fine, cranks like champ, but wont start. i checked and had no spark on all cylinders.
i have tested the kill circuit by disconnecting mercury switch and disconnecting blk/yel to switch boxes, tested the neutral interlock switch, tested rectifier (which is visibly blown out see pic) by removing yellow wires, also disconnected entire wire harness and jumped the starter. still no spark. the red/white wire from my idle stabilizer was burnt/corroded so i cut out the bad section and replaced with new wire (this was burnt and corroded before i lost spark--see pic). checked resistances with below results...seems fine to me. i havent replaced the spark plugs yet cause i cant believe that all of them could be fouled at once/all of a sudden. nor have i checked the ignition coils because my wire colors didnt match the manual and i dont see how all could fail at once.
STATOR
blue/white to red/white = 6.47 kO (supposed to be max of 6.2...)
red/white to ground = 150 O
blue to red = 6.29 kO (supposed to be max of 6.2)
red to ground = 138 O
TRIGGER
black to ground = 0.00
brown to white (yellow sleeve) = 1.3 kO
white to violet (yel) = 1.299 kO
violet to brown (yel) = 1.302 kO
any other ideas? is 6.47 kO when its supposed to be 4.5 - 6.2 OK? could that explain why the rectifier crapped out in the first place?
please start with simple solutions first...based on my testing i think it has to be something simple...something i am overlooking. i thought the rectifier is just involved with the charging circuit, can it prevent the spark? i have another ignition switch...should i try putting that in?
thank you for the help. see pics here: http://picasaweb.google.com/leallyn.murtagh/Mako?feat=directlink
