Mercruiser 3.0 I/O bogging down

[Steve24249]

Hi all, thanks for reading. I have an issue I’m trying to fix. I have a new to me 2000 Stingray 190 RS with a 3.0 Mercruiser I/O 135 hp. I’ve had it a few months. Everything was great up until last week. I filled up the tank on the lake, cruised back to my mooring, and went home for the weekend. Came back a week later and boat started up just fine. Idled great. I started heading out of the no wake zone and throttled up…it delayed and bogged down, so I slowly pulled it back and it was fine. I gave it throttle again and it went just fine. I was cruising around no problem. Sometimes it was giving the ever slightest delay when throttling up. I left and went home that day and came back up today. It started up super easy. Idles great. Can idle up with no problems whatsoever. I once again start to go and get out of the no wake zone, and it starts to bog down again. So I pull back on throttle a bit so it doesn’t stall. After that, it was running just fine. Any ideas what could be causing this? Thanks in advance. My guesses have been water in the fuel or bad fuel filter? Ive also heard fuel pump.

 

[MC_What have I done?!]

Following.

I am having the same issue with my 3.0 but haven't looked into it yet. The first thing I am going to check is my tank vent, can't really tell if it has fuel or water in it from looking but I'm going to take a straw and try blowing into it with the fill lid off. If there is resistance, I think that the could be the cause of the stalling at higher rpms.

 

[nola mike]

Hi all, thanks for reading. I have an issue I’m trying to fix. I have a new to me 2000 Stingray 190 RS with a 3.0 Mercruiser I/O 135 hp. I’ve had it a few months. Everything was great up until last week. I filled up the tank on the lake, cruised back to my mooring, and went home for the weekend. Came back a week later and boat started up just fine. Idled great. I started heading out of the no wake zone and throttled up…it delayed and bogged down, so I slowly pulled it back and it was fine. I gave it throttle again and it went just fine. I was cruising around no problem. Sometimes it was giving the ever slightest delay when throttling up. I left and went home that day and came back up today. It started up super easy. Idles great. Can idle up with no problems whatsoever. I once again start to go and get out of the no wake zone, and it starts to bog down again. So I pull back on throttle a bit so it doesn’t stall. After that, it was running just fine. Any ideas what could be causing this? Thanks in advance. My guesses have been water in the fuel or bad fuel filter? Ive also heard fuel pump.

Start with changing your fuel filters. Empty your fuel/water canister filter into a clear container and see if you have any water/crud in there...

 

[Steve24249]

Following.

I am having the same issue with my 3.0 but haven't looked into it yet. The first thing I am going to check is my tank vent, can't really tell if it has fuel or water in it from looking but I'm going to take a straw and try blowing into it with the fill lid off. If there is resistance, I think that the could be the cause of the stalling at higher rpms.

Ok thank you both for the reply. I will get a filter and change it out Friday.

Looks like I have a combo fill/vent. Should I take a straw and blow into it to make sure I have no resistance ?

 

[nola mike]

Ok thank you both for the reply. I will get a filter and change it out Friday.

Looks like I have a combo fill/vent. Should I take a straw and blow into it to make sure I have no resistance ?

Doesn't sound like a plugged vent, but just unscrew your gas cap when it happens. If you don't get a rush of air in there it isn't the vent. Or leave the cap off and see if the problem is still present