Hello,
I am new to this site and excited i found it. My 1998 Mariah Shebah 180 Mercruiser 4.3 liter I/O with 155 hours is losing power after about an hour of use. I will go on the lake and the boat will run fine for about 30 minutes or an hour of drive time. Usually, after pulling the kiddos tubing, I’ll beach it for an hour or so and then went I go to cruiser, it lags significantly. On one occasion, it wouldn’t even plain out. Had to wait about 10 minutes and tried it again and it plained out but the engine lagged significantly. It doesn’t sound like it is misfiring, but rather losing power somewhere (not backfiring). I’ll be cruising at 30 mph and the engine will lag for a couple second and then kick back to normal p[FONT=Arial, Helvetica, sans-serif]ower and continually do this every 10 or 15 seconds. During this time, the rpm will fluctuate between 3000 and 4200. This will occur every 10 or so seconds. The RPMs fluctuate with the loss and re-gaining of power. After it starts doing this, we will take it off the lake and after sitting overnight or a week, we will take it back out and the same process happens over again; runs fine for the first hour or so then starts losing power. [/FONT]
[FONT=Arial, Helvetica, sans-serif]i brought it to the shop and they put it on the dyno and it said it was something with fuel. The changed the water separator and anti siphon value. I was excited that it was a minor fix. New gas in tank as well. Well sure enough, brought it on the water and same thing. Brought it back in and dyno said nothing was wrong. they checked the fuel pressure, vacuum, distributor, fluid level, fuel test (no water in gas) etc and nothing. Gas is good and fresh, via there test. All the in line filters are clean. They took it on the lake quickly and it ran fine, which it always does at first. We got it back yesterday and brought it out today (2nd new tank of gas). Of course, it happened again so i videoed it and sent it to the marine shop. not sure if we can post videos on here (might help some of the experts on here) Well, due to the shop being so busy with winterization (live in Minnesota) they said they cant figure it out and to being back in spring if it continues. The marine shop didn’t want to just start replacing parts they thought were the problem until the kinda knew. Does anyone have any advice. I fear they won’t figure this out and it’s frustrating. It doesn't sounds like the shop put much time into it, to be honest. Maybe something to do with having a load (tubers). Seems to happen after pulling. Has anyone on here heard of problems like this?Any advice or thoughts would be appreciated. I am not a mechanic nor pretend to be one.
Thanks in advance,
Adam
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I am new to this site and excited i found it. My 1998 Mariah Shebah 180 Mercruiser 4.3 liter I/O with 155 hours is losing power after about an hour of use. I will go on the lake and the boat will run fine for about 30 minutes or an hour of drive time. Usually, after pulling the kiddos tubing, I’ll beach it for an hour or so and then went I go to cruiser, it lags significantly. On one occasion, it wouldn’t even plain out. Had to wait about 10 minutes and tried it again and it plained out but the engine lagged significantly. It doesn’t sound like it is misfiring, but rather losing power somewhere (not backfiring). I’ll be cruising at 30 mph and the engine will lag for a couple second and then kick back to normal p[FONT=Arial, Helvetica, sans-serif]ower and continually do this every 10 or 15 seconds. During this time, the rpm will fluctuate between 3000 and 4200. This will occur every 10 or so seconds. The RPMs fluctuate with the loss and re-gaining of power. After it starts doing this, we will take it off the lake and after sitting overnight or a week, we will take it back out and the same process happens over again; runs fine for the first hour or so then starts losing power. [/FONT]
[FONT=Arial, Helvetica, sans-serif]i brought it to the shop and they put it on the dyno and it said it was something with fuel. The changed the water separator and anti siphon value. I was excited that it was a minor fix. New gas in tank as well. Well sure enough, brought it on the water and same thing. Brought it back in and dyno said nothing was wrong. they checked the fuel pressure, vacuum, distributor, fluid level, fuel test (no water in gas) etc and nothing. Gas is good and fresh, via there test. All the in line filters are clean. They took it on the lake quickly and it ran fine, which it always does at first. We got it back yesterday and brought it out today (2nd new tank of gas). Of course, it happened again so i videoed it and sent it to the marine shop. not sure if we can post videos on here (might help some of the experts on here) Well, due to the shop being so busy with winterization (live in Minnesota) they said they cant figure it out and to being back in spring if it continues. The marine shop didn’t want to just start replacing parts they thought were the problem until the kinda knew. Does anyone have any advice. I fear they won’t figure this out and it’s frustrating. It doesn't sounds like the shop put much time into it, to be honest. Maybe something to do with having a load (tubers). Seems to happen after pulling. Has anyone on here heard of problems like this?Any advice or thoughts would be appreciated. I am not a mechanic nor pretend to be one.
Thanks in advance,
Adam
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