Need some serious help with my 1993 20hp 2stroke merc

[onthewater102]

Here is a picture of the WRONG part - this is visually no different only it's sold as a "MALE HOSE CONNECTOR" and therefore has a different check valve installed in it. In every way including the post mount positions it looks JUST like the engine side connector.

 

[scoobeb]

Nope,it's not that part,I have used 2 brand new tanks and 2 brand new lines with the new mercury connection and the other is a Tohatsu tank and line and they both do exactly the same thing for the engine,still starves for fuel unless I keep priming the ball.

 

[scoobeb]

Here is both tanks and lines I tried so far,brand spanking new,

 

[scoobeb]

Top is a 3 gallon tank,bottom is a genuine mercury quicksilver ta b k and line.

 

[perchjerker]

Did you test the float like I told you

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[onthewater102]

You can put 1,000 new and different tanks on it - if you changed the ENGINE side connector and replaced it with a hose connector it won't matter what tank you use your results will be the same.

I put up a picture of the other style mercury fuel connection - the same would hold true with the style you have if you put a hose connector on the engine.

 

[JL8Jeff]

I had that situation last year, it would bog down when giving it throttle. Turned out the fuel line connection at the motor was not seated all the way and it was letting air in. There wasn't a fuel leak, but I could see the air bubbles in the fuel filter. Did you look at the filter and lines (if they are clear lines) while it's running to see if you can see any air bubbles? It sounds like either the fuel pump is bad or you have a vacuum leak in the fuel system.

 

[scoobeb]

I just replaced the male fitting on the engine a little over a month ago as well as a new carb gasket kit.This is frustrating.It has been raining here for a while now,once it quits i am going to start doing one thing after another to eliminate it all one by one,my last step is taking the carb off.I am going to check the new gasket on the fuel pump to make sure there is no pin hole leaks somehow.I was told if i pump the ball hard from the start,take the fuel tank and lift it well above the engine it should automatically gravity feed itself because the fuel pum really won't have to work much,if indeed that works i believe there is something in the fuel pump defective.There is a check valve spring that seems to working properly and looks in great shape,the plastic hard body of the fuel pump seems in great working order so who knows.It's probably something so darn simple.I will put the old male fuel fitting back on the engine if all else fails to see how that works.

 

[scoobeb]

I do get air bubbles when priming the ball into the fuel filter,i'm not quite sure what you mean by seated JL8JEFF,No i don't have clear lines.

 

[scoobeb]

I had that situation last year, it would bog down when giving it throttle. Turned out the fuel line connection at the motor was not seated all the way and it was letting air in. There wasn't a fuel leak, but I could see the air bubbles in the fuel filter. Did you look at the filter and lines (if they are clear lines) while it's running to see if you can see any air bubbles? It sounds like either the fuel pump is bad or you have a vacuum leak in the fuel system.

So how did you fix the issue because i have now used to brand new fuel tanks and lines with the same results.

 

[crazymanme2]

Get a small lawn mower battery and hook up a small electric fuel pump and test it out.
Every thing I see points to a bad fuel pump.

 

[scoobeb]

UPDATE/FIXED:::::::::::::::::::::::Ok,you guys are not going to believe how much of a dummy i am.I for the life of me knows i put everything back in correct, i was so lost.I guess while i was putting the carb gasket in between the carb and the power head i must of totally forgot i put the wrong gasket on.The gasket fit so perfect when i installed it and i never paid enough attention to it and this whole time it was just a stupid mistake i made and so simple to fix.What a complete dummy i am.I tore the fuel pump apart 3 times and switched gaskets,etc,changed fuel lines and tanks and fittings and all it was this whole time was one dumb simple mistake i made by not paying attention to my work as i must of got side tracked working on another part of the outboard and forgot to switch to the right gasket,well at least it was one simple easy fix and i'm glad i didn't start unloading money for no reason at all. Thanks to all that chimed in to help me,i finally got it right after all the hard work i put in it.

 

[perchjerker]

After reading through your posts I believe it. Glad it's fixed just don't come back saying it's not lol

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[JL8Jeff]

I did that on an old 69 Camaro 6 cyl engine one time. I had a gasket flipped around in the 1 bbl carb. My problem last year was the fuel line became unseated at the engine connection. It clicks into place with the spring loaded clip and I think it got pushed in by the shift cable and became unseated slightly. It let air into the fuel line and I could see it in the filter.

 

[scoobeb]

Crazy,I can't believe I did that,now on Monday is test number 2 day. The motor itself is just insane as far as power. I have bought and sold many 25hp 2stroke Mercury's at least 5,this 20 is the most powerful 20hp 2stroke I have ever witnessed In my days. It has 30hp power hands down. This 20 pushed near 1000lbs at 28.5 mph. The 25hp merc I used to have ran much less weight at only 28mph,that was a much smaller boat also. This motor just seems like it has so much more power than most 20 or even 25hp I've seen. I have read in many threads on many different forums about this very thing,about some of the earlier 2stroke Mercury's in like the 80s-early 90s were just built over powered and ran much faster and more powerful then all the other mercs from any other era. Any real truth to this? I do know it's well documented on allot of different places. I tend to believe it's true after seeing what this merc did as far as performance.

 

[scoobeb]

After reading through your posts I believe it. Glad it's fixed just don't come back saying it's not lol

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I can't believe what a simple fix it was.Unreal.It runs like a raped ape now.The only other issue is i don't know if i have the fuel/air mixture screw perfect is there is such thing.I know it idles great,well a bit rough as of now because i added some extra oil and a full can of Seafoam to the first tank because it hasn't been run in many yrs,other than that it seems to run perfect.I go from a full stop to wot without a hiccup at all so i must have it somewhat right.My question is,is there any such thing as having it perfect or is what i'm experiencing from going from stop to wot without a hiccup as good as i can ask for?I checked the plugs after the first run and they were like a nice dry tan brown,from what i gather that is were it should be.

I have always read though it is better to run a hair on the rich side then lean so maybe i should turn the fuel/air mixture screw out a hair bit more rich.I am going to pull the plugs Tuesday as that is the next day i'm going out,clean them completely off like new again and then determine how she runs,or i may just wait till i have the next tank with the perfect 50:1 oil because now is not a fair judgement on the plugs with all the extra oil and seafoam,The lake i go to is not very big as i can go from side to side in less than a minute or so,now i'm not complaining i just wish i had a bigger lake to go to.I am going all next week to finish my first tank of gas with the extra bit of oil i put in it then it's off to the gulf to go catch some nice Snook,Trout,and Redfish among other species.Sharks should be in soon and they are fun to catch on a 16ft jon boat,lol.