Hello. First time poster here. I have read these boards over time, and have appreciated the information. Thank you. Hoping to get a little advice.
I have 1995 Malibu Echelon with a Mercruiser 350 Mag Tournament Ski. S/N OF350523. We bought it when it was a couple of years old and it has been an awesome boat. It has only about 400 hours, has always been kept dry and well serviced. Have done almost nothing to it other than regular maintenance things.
It has been run very little the last couple of years. This season, it is running rough and bogs down at top end. I initially was confident I had a fuel issue (and may), but driving it today, it really seems to be more of a dead miss to me. It sounds fine on the trailer with a hose. The issue appears under a load.
Initially thinking a fuel issue, it had a new fuel filter last year. I pulled it today and dumped the fuel from the filter in a jar. It looks and smells just fine. We have kept Stabil in it always. The injectors on top of the throttle body seem to be making nice little cones, but I don't know what they are supposed to look like. I'd like to put a fuel pressure gauge on it, but I can't see how to do that - the high pressure lines are formed metal, and I see no Schrader valve on the VST. The air cleaner (or whatever its called) seemed pretty clogged, and it cleaned that up. I put a little injector cleaner in the throttle body and dumped the can in the fuel tank, though not really expecting much from that. Not sure what else to do chasing a fuel issue at this point, if anything. I guess if I was going to take a next step, besides pressure testing the high pressure pump, it might be to take apart the VST - I think there is a screen on the bottom of the pump (is that true for mine?) that I would want to check.
After doing those things, I ran it again today. Today, the issue seemed somewhat variable. Initially, I felt/heard a dead miss, even just cruising at idle or a little above. Planing off, I thought it was going to run out okay. Then, with more throttle, it was clearly not right. I tried to diagnose the miss pulling one plug wire at a time and running it, comparing to how it was running before - found one suspect, but not positive. Then I ran it again at WOT. For a time I thought maybe it was running normally. Not positive about my speed because one of the speedos is off, and I am not sure which. The higher reading one read about 36 which wouldn't be too far off its top end. RPM's maxed out at about 3400. Ran it at WOT for maybe a minute or two - during that time - you could hear it intermittently bog down slightly for just a few seconds.
Just listening to it today, it seems more like a dead miss, and I am thinking ignition. Plug wires were replaced once but that has been a long time ago, like 15 or more maybe. Wondering whether moving the wires made it run better. I am planning to replace those and the plugs and see what happens. Anything else I should do to troubleshoot the ignition? I am confident that the distributor, coil and other ignition components are original.
I would welcome any and all suggestions! Thanks for any input!
I have 1995 Malibu Echelon with a Mercruiser 350 Mag Tournament Ski. S/N OF350523. We bought it when it was a couple of years old and it has been an awesome boat. It has only about 400 hours, has always been kept dry and well serviced. Have done almost nothing to it other than regular maintenance things.
It has been run very little the last couple of years. This season, it is running rough and bogs down at top end. I initially was confident I had a fuel issue (and may), but driving it today, it really seems to be more of a dead miss to me. It sounds fine on the trailer with a hose. The issue appears under a load.
Initially thinking a fuel issue, it had a new fuel filter last year. I pulled it today and dumped the fuel from the filter in a jar. It looks and smells just fine. We have kept Stabil in it always. The injectors on top of the throttle body seem to be making nice little cones, but I don't know what they are supposed to look like. I'd like to put a fuel pressure gauge on it, but I can't see how to do that - the high pressure lines are formed metal, and I see no Schrader valve on the VST. The air cleaner (or whatever its called) seemed pretty clogged, and it cleaned that up. I put a little injector cleaner in the throttle body and dumped the can in the fuel tank, though not really expecting much from that. Not sure what else to do chasing a fuel issue at this point, if anything. I guess if I was going to take a next step, besides pressure testing the high pressure pump, it might be to take apart the VST - I think there is a screen on the bottom of the pump (is that true for mine?) that I would want to check.
After doing those things, I ran it again today. Today, the issue seemed somewhat variable. Initially, I felt/heard a dead miss, even just cruising at idle or a little above. Planing off, I thought it was going to run out okay. Then, with more throttle, it was clearly not right. I tried to diagnose the miss pulling one plug wire at a time and running it, comparing to how it was running before - found one suspect, but not positive. Then I ran it again at WOT. For a time I thought maybe it was running normally. Not positive about my speed because one of the speedos is off, and I am not sure which. The higher reading one read about 36 which wouldn't be too far off its top end. RPM's maxed out at about 3400. Ran it at WOT for maybe a minute or two - during that time - you could hear it intermittently bog down slightly for just a few seconds.
Just listening to it today, it seems more like a dead miss, and I am thinking ignition. Plug wires were replaced once but that has been a long time ago, like 15 or more maybe. Wondering whether moving the wires made it run better. I am planning to replace those and the plugs and see what happens. Anything else I should do to troubleshoot the ignition? I am confident that the distributor, coil and other ignition components are original.
I would welcome any and all suggestions! Thanks for any input!
