Mercury 150 not running right

[BRWNBR]

I’m at 56 hours. Changed oil recently, replaced in line fuel filter, dumped fuel separator. Motor runs strong for a while then begins to surge, seems to surge worse on bumps or waves. Power is slowly lost. If I sit for a while at idle I get a good couple minutes then it starts to surge and power down again. Gotta get bear bait pulled by Monday....
Anyone have thoughts I can try? Any boat place is gonna be two weeks out to fix it.

 

[Garyak]

Similar symptoms for me turned out to be idle air control valve. Just a thought as I am far from being a mechanic.

 

[BRWNBR]

Does that effect the idle? I seem to be idling just fine.

 

[BenC]

What do you mean you dumped the fuel separator? Did you just drain the bleeder valve or dump the whole filter? If you drained the whole filter, I'm pretty sure your supposed to fill it back up with clean fuel before reinstalling. Sorta sounds like a fuel issue.

 

[BRWNBR]

Drained it. Then pumped it back full. Ran solid for
About a half tank. Then same issue again today. Wondering about fuel
Pump...

 

[Garyak]

Does that effect the idle? I seem to be idling just fine.

That was the oddball part. It would start and idle just fine with no warning lights until power was applied and about when I'd get on step it would begin to surge and then, I'd get the "check engine light". I fiddled with it until I could maintain about 12 mph and got home. Shop said it ran perfectly after servicing (or replacing) IAC valve...but they also flushed the injectors since it was there and on the stand. Never had the issue again. The whole bill was about a hundred bucks @ Anch. Yamaha/Suzuki in Spenard. You may have a something different going on. Sounds similar, though.

 

[BenC]

Drained it. Then pumped it back full. Ran solid for
About a half tank. Then same issue again today. Wondering about fuel
Pump...

Oh ok, at first it sounded like it just wasn't primed up all the way. The problems started after maintenance though correct?

 

[Garyak]

Might pay to call/quiz Jeff..service manager at Bass Pro or a valley Merc dealer. Sounds like a new outboard...still under warranty?

 

[BRWNBR]

Might pay to call/quiz Jeff..service manager at Bass Pro or a valley Merc dealer. Sounds like a new outboard...still under warranty?

2017 I think. One year left. Forgot bass pro is a Merc dealer...

 

[BRWNBR]

Oh ok, at first it sounded like it just wasn't primed up all the way. The problems started after maintenance though correct?

Problem started about four tanks of gas after oil change. Then I did the filter and fuel flush in seperator thinking it was that. But it must not have been.

 

[Troy Sharp]

Sounds like air in the system, primer bulb lose prime at all?

 

[AK2AZ]

The first things I would look for...air in the system and obstruction at the tank sender.

 

[BRWNBR]

Pulled the tank apart everything looks good in there, haven’t found anything leaky or loose yet. It’s just gonna gonto a dealer and let them try to figure this out.

 

[Daveinthebush]

If the tank is built into the boat, does it have an anti-syphon valve?

 

[Frostbitten]

I believe Troy and AK2AZ are on to something there. I had a similar issue years back, turns out a fuel line had a small crack where it terminated to a fitting. It didn’t leak fuel out, but under power it was sucking air in. Replaced the line and it ran like a champ.

 

[BRWNBR]

Should my connection be sweating this much? I took the hose off and tightened it one whole turn without much effort.

Sent from my iPhone using Tapatalk

 

[Garyak]

No...not unless your tank is over filled.

 

[BRWNBR]

No...not unless your tank is over filled.

It’s half empty right now when I took this pic.

 

[refak83]

Hard to tell in the picture but it looks like your connector is not quite all the way on. You should not have the “sweat” in your connection area. Check the o-ring in the end of your fuel hose connector.

 

[Daveinthebush]

If that wet area is gas you have a sealing issues somewhere. That connection rotates 360 degrees. I'd check all the fittings and connections one-by-one.