I have a 1994 Mercury 2.5L XRi (EFi) 200HP Black Max that is having starting issues. The boat sat for several years with very little use until I basically acquired it last year. Over the last year I had the boat in the shop for various different repairs ranging from a tune up to the replacement of a few things due to the boat sitting for so long. Two weeks ago while at Broken Bow Lake the boat would not start the first morning on the water, but finally did start after I hard started it (setting it where the throttle is forward and cranking it). The boat started the remainder of the trip, usually within 2-3 tries. Last Tuesday morning when I put it in the water it would not start at all and after several attempts, the starter went out (the starter was on it's last limb and I knew it was going to need replacing soon anyways). I ordered a new starter and was able to replace it the next day along with replacement spark plugs and fixing a few small leaks in a few hoses that I found in the process. I ran the boat at the house after replacing the starter and it started and ran like a champ. On Friday morning when I went to put it in the water, once again, it would not start, even while trying to hard start it. After trolling around and fishing for a bit, I tried to start it again but this time I switched gas tanks from tank 2 to tank 1 and after a hard start, it fire right up and ran well. I switched back to tank 2 and it started just fine but eventually went back to tank 1. Later that evening I took the wife out for a bit and I noticed that the boat was not starting on on the first try the majority of the time, but would after a few tries. It would turn over and almost start with a quick turn of the key or would start and quickly die before I put it in gear. Sometimes I would have to give it a little throttle right after it started and it would run just fine.....sounding like it just wasn't getting juice or power initially after the start. I've also noticed that the hole shot is slower, with the motor not getting the boat on plane for a good 5 plus seconds or so. Friday afternoon before going back to the lake, I ran some Sea Foam through it at the house and also ran some through it that evening while on the water.
Note: When the motor was not starting, it would continuously turn over with occasions where it would almost fire off. When it is turning over, it sounds as if it's turning over as it should. Also, while starting it at home and out of the water (but connected to the water hose), it would start right up no problem, but once it was in the water, it would not start.
I'm not very mechanical when it comes to motors. I would love to just take it to the shop again but the wife and I have twins on the way that will be here in a few months so I'm trying to save money and hopefully get the problem fixed myself.......and fish as much as possible before the arrival of the twins. To me it seems as if it is a firing or fuel issue.
I don't know it is a fuel problem or a firing problem, but to me it seems as if it is one or the other. I've checked everything I know to check related to both a possible fuel or firing problem, but nothing pops out to me as a possible problem. As of the last time I was on the water which was Friday evening, it was running fine for the most part other than having to crank it a few times each time, most of the time, I'd go to start it with some of those times seeming as if it was struggling a tad to get going. Thank you for any help or info that you may have with helping me with this issue. I was going to go out on the water this afternoon and see how it was going to start and run, but we just had some pop up storms with lightning so I probably won't go today. Thanks again!