*Help with my Merc 3.0 fuel issue*

[jarheadtex]

Today I took my boat out for the first time this season. It is a 1995 bayliner 1850 with a Mercruiser 3.0. It ran fine for the first hour or so then it started bogging while under way almost like it was flooding. I would have to stop...wait a minute and take off again. Any ideas? I figure something with the carb...

 

[Bondo]

Re: *Help with my Merc 3.0 fuel issue*

Ayuh,.... Sounds like crud in the fuel to me,...

Check, 'n change the fuel filters...

 

[jarheadtex]

Re: *Help with my Merc 3.0 fuel issue*

Ayuh,.... Sounds like crud in the fuel to me,...

Check, 'n change the fuel filters...

Thanks, Ill give that a try

 

[DriftingAway]

Re: *Help with my Merc 3.0 fuel issue*

Im no expert or anything but you sound like your having some of the same issues Im having. There are 2 fuel filters i have been told to check and replace. The 1 on the bottom of the fuel pump and the other is where the line from the pump runs into the carb. Hope that helps you.

 

[jarheadtex]

2nd time out and I still have bogging problem....help please

2nd time out and I still have bogging problem....help please

The first time I took the boat out after winter it ran like a champ for an hour. Every since it will go under load for about a minute under full throttle until it bogs. I can putt around all day at 1500 rpm and its fine. I can go full throttle for a minute and it will bog. I can stop and it will be fine for another minute of full throttle action. I have used gas with ethanol many times last season and never had an issue. I cleaned the carb and looked for any filters to change but no luck. Its kinda hard to test in the drive way. Any suggestions?

oh..its a bayliner 1850/3.0 mercruiser

 

[jarheadtex]

Re: *Help with my Merc 3.0 fuel issue*

i looked for this filter on the carb but had no luck. I will change the fuel filter this weekend. Did this fix your issue?

 

[achris]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Fuel pump, anti-syphon valve, collapsed pickup in the fuel tank, filter in the carb.... Something is restricting fuel flow to the carb....

 

[jarheadtex]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Fuel pump, anti-syphon valve, collapsed pickup in the fuel tank, filter in the carb.... Something is restricting fuel flow to the carb....

where is the filter in the carb?

 

[fat fanny]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Right behind the line going into the carb from the fuel pump

 

[mark1905]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

where is the filter in the carb?

You need to completely unscrew the fuel line and fitting from the carb, and there will be a round nylon screen that fits up in there. It pops right out for cleaning. If you've never done this, there's a very good chance that this is your culprit.

 

[jarheadtex]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

You need to completely unscrew the fuel line and fitting from the carb, and there will be a round nylon screen. that fits up in there. It pops right out for cleaning. If you've never done this, there's a very good chance that this is your culprit.

Sorry for the noob type questions. I did ALOT of research last night and found a PDF diagram for everything I need.

 

[mark1905]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Sorry for the noob type questions. I did ALOT of research last night and found a PDF diagram for everything I need.

We've all been there.. no worries! Good luck.

 

[mpdive]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Sounds like a bad float level to me. Would explain the isolated rpm problem.

 

[achris]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Sounds like a bad float level to me. Would explain the isolated rpm problem.

Really!!?!?!? Low float level would have an immediate effect, not delayed.... Sounds more like the float chamber is filling up at low demand, then the supply isn't enough to meet the full load demand and the fuel level in the float chamber is dropping, leading to the loss of power...

 

[fat fanny]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

I would reccomend that the OP due the no cost trouble shooting 1st before tearing into the carb to ensure he is getting the proper amount of fuel to maintain the need of the carb as listed above tanks pick up tube and screen,anti siphon valve, vent and filters and water test then move onto the carb which will involve cost possible re-build kit and carb dip. I think we always give great advise and tips but must maintain the proper trouble shooting proceedures to educate and avoid unecessary part changing and finding root cause solutions especiallly with an issue such as this which comes up more times than I can count this time of year. I'm leaning toward fuel supply was debri drawn up through the system and clogged filters and also moved onto carb.

 

[mpdive]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Really!!?!?!? Low float level would have an immediate effect, not delayed.... Sounds more like the float chamber is filling up at low demand, then the supply isn't enough to meet the full load demand and the fuel level in the float chamber is dropping, leading to the loss of power...

Uh Yea......A low float level could very well cause this. May be enough to feed the main metering and idle on low demand but could definately come up short on enrichment demand.

 

[fishrdan]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Did you change out the fuel pump filter yet and if so, how did it look, clean or garbaged up?

On the cheap, you can pull the filters and inspect them to see how they look, won't cost anything to see if the filters are plugged up.

Oh yeah, don't use anything but "line wrenches" (or box end wrenches) on the fuel fittings/lines or you could round over the fittings. Don't cheap out on buying line wrenches either as a cheap, loose fitting line wrench could round over the fittings just as easily as an open end wrench.

 

[achris]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Uh Yea......A low float level could very well cause this. May be enough to feed the main metering and idle on low demand but could definately come up short on enrichment demand.

Then it wouldn't run well for a minute then bog, the lean condition would present immediately...

 

[mpdive]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

No.....Depending on how low the adjustment was it would present driveability on the upper throttle end. Your post said low level would fill the bowl at low demand. Low float level equals early seating of the needle and in turn low fuel level. There would always be a level of driveability thus compromised. This would be fine for idle and cruise but would definately starve at WOT. (unless I misunderstood your post) Not pickin at ya either You have a lot of great knowledge shared here..

 

[jarheadtex]

Re: 2nd time out and I still have bogging problem....help please

Re: 2nd time out and I still have bogging problem....help please

Did you change out the fuel pump filter yet and if so, how did it look, clean or garbaged up?

On the cheap, you can pull the filters and inspect them to see how they look, won't cost anything to see if the filters are plugged up.

Oh yeah, don't use anything but "line wrenches" (or box end wrenches) on the fuel fittings/lines or you could round over the fittings. Don't cheap out on buying line wrenches either as a cheap, loose fitting line wrench could round over the fittings just as easily as an open end wrench.

I ordered a new fuel filter. As soon as it gets here...hopefully this weekend Ill pull both filters and see whats going on there.
I have a full compliment of line wrenches...but didnt even think to use them. Ill post up what I find. The boat idles fine amd I can put around all day at 1500 rpm.....but can only go WOT for maybe 45 seconds.

thanks for all the input.