Thread: 1996 Mercury Optimax 75hp

Put the boat out on the water for the first time this year. Took my 12 year old son, and we just had a blast....caught about 150 total in about 3 hours, and kept 16 that were between 10.5" and 13". I'm ok with the fact he caught 4 that were between 12" and 13".....pictures to prove it! LOL

Well, put the boat in, took a couple times cranks to get it purring....ALWAYS DOES! So, we took off from the boat ramp, ran it at 35mph no problem to spot #1. Fished for awhile, then decided to hit spot #2. Fired up the big motor, and scooted over to the next spot. Fished for awhile, fired up the big motor, then off to spot #3. Got done there, and headed down to the last spot with the big motor. Fished for awhile there, then went to fire up the big motor, and couldn't get it to fire. IT NEVER SPUTTERED, IT NEVER SPIT, IT NEVER HESITATED, IT NEVER NOTHING! IT RAN PERFECT, AS IT ALWAYS DOES! It sounded like it was "spinning faster" when it tried starting....almost like when you try to start something without gas in it. I checked the bulb....primed. I made sure the electric choke was working and not stuck on. I even popped the fuel line off and put it back on....just in case. I had some rainbow on the water. So, trolled the last mile back to the dock at a whopping 3mph....but made it!

Now, when I got it back up on the trailer and out of the water, I had mixed oil and gas coming from the lower unit. I figure it is overflow from somewhere, just following the easiest path due to gravity. I'm sitting here in my house, a few miles from my boat, running through everthing in my head, but sick to my stomach thinking about what it could be/how much to fix it/preacher's annual fishing trip in 2 weeks. GOTTA HAVE THE BOAT DONE!

Thoughts and questions:
1. It ran too good, with ZERO ISSUES, then just didn't want to work. Can't be anything huge!
2. Kill switch? If the kill switch clip was popped off enough, could enough gas be pumped trying to start it that it could "overflow" somewhere?
3. Possible gas line somewhere pop off. DOES ANYONE HAVE A DIAGRAM/SCHEMATIC OF A FUEL SYSTEM FOR A 1996 Mercury Optimax 75hp they would be willing to share?
4. WHAT OTHER CRAZY THING COULD I BE MISSING?

Any help would be MAJORLY appreciated. I am not afraid to tear into something, but I'm about out of time. I'm going to try to look at it after church tomorrow morning. But, any direction, warnings, thoughts, or ideas would be GREATLY appreciated. If I can't get it done before my trip starts in a couple weeks, I have a river boat I can use; however, my bassboat is just SOOOOO much more comfortable for spending 7 days on the water!

mrwillis

First thing you need to do at home , pull cowling off motor, pump primer bulb , see if you have a leak. If no leak. Have someone turn key on ( not start) and listen for high pressure pump come on then go off. Look for leaks. If you don't hear high pressure fuel pump cycle once. Then look at fuel pump fuse.