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Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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I have a 2006. 115 Mercury 2 stroke will not accelerate over

Customer Question

I have a 2006. 115 Mercury 2 stroke will not accelerate over 4000 rpm. Changed plugs. Changed fuel lines. Changed computer. Good compression all wires firing. Number 2 plug a little wet. Mechanic put on computer. Computer says all systems functioning properly. Evidently there not. He is stumped. And so am I.
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.

Hello, my name is***** will assist you.

Is the #2 plug more black that the others?

Customer: replied 1 year ago.
Just a little but not much. 1 an 2 are good an tan.
Customer: replied 1 year ago.
Kinda seems like it wants to flood out at beginning of reverse and forward the picks up runs decent up to 4000 rpm. But will not advance any further.
Expert:  Charles replied 1 year ago.

Is the throttle butterfly still getting to wide open throttle?

Was the fuel checked for water?

Does it idle well?

Customer: replied 1 year ago.
Mechanic checked all fuel pressure it was fine. New fuel numerous times. Been having this problem for 3 weeks. Mechanic keeps changing stuff. Nothing seems to help. Problem just started all of a sudden in just one day.
Customer: replied 1 year ago.
Will idle decent in neutral. But not in gear. Forward or reverse.
Expert:  Charles replied 1 year ago.

Ok, are you near the boat now?

Customer: replied 1 year ago.
Yep. Sure am.
Expert:  Charles replied 1 year ago.

Ok, look at the fuel line from the boat to the engine. It is gray with red writing?

Customer: replied 1 year ago.
Yep just put a new fuel line on Saturday. Thought it might be collapsing inside. Because of the ethanol in the gas around here.
Expert:  Charles replied 1 year ago.

Was it?

Can you remove the fuel filter and look inside the chamber for signs of debris?

Customer: replied 1 year ago.
Put a new fuel filter on Saturday.
Customer: replied 1 year ago.
Mechanic has already checked and cleaned all injectors. Good pressure there. Can't help but think it's a electrical problem.
Expert:  Charles replied 1 year ago.

Was the chamber looked at inside it. I am looking for certain signs.

Customer: replied 1 year ago.
No. Just changed it all to new. Still didn't change anything.
Expert:  Charles replied 1 year ago.

If there is debris in the chamber, it is also inside the low pressure pump. that is why I am asking.

Customer: replied 1 year ago.
Forgot to tell you he Also changed the injector bar or something like that. Not really sure what that is.
Expert:  Charles replied 1 year ago.

the fuel rail? Close to $1000?

Any luck on the fuel filter?

Do you have a pressure gauge that can read at least 50 PSI?

Customer: replied 1 year ago.
Yea I no cheap. I think he is afraid to tell me he is stumped. Nothing he tries changed it. the only thing I have where I'm at is a tire pressure gauge. I would assume he checked the pressure. He said he did and it was fine. But you no how that goes sometime.
Customer: replied 1 year ago.
Also thought I would tell you when I shove the throttle wide open no gain in rpm. But sucks the fuel.
Expert:  Charles replied 1 year ago.

Sorry for the delay, I had back to back phone customers.

Ok, I am not stumped, I just need you to look at the things that I recommend to you, weather he has already done so or not. I am not a part changer, I am a tech. I locate the problem before ever telling you to replace a part.

So can you take out the fuel filter and have a look inside the bottom of the chamber?

for a pressure gauge, you can go to most chain auto parts stores and rent one that can read over 100 PSI and we can use that to do all of the testing that I am going to need done.

Customer: replied 1 year ago.
I got a gauge that will read 60 dark here in kentucky right now can't see outside. But I will do that first thing tommorow. And get back with you.
Expert:  Charles replied 1 year ago.

Ok, I am in Arkansas so I understand.

With the gauge. Hook it to the fuel test port on the fuel rail. Use the primer bulb and pump it until it is firm. Turn the key on, watch the fuel pressure on the gauge. I need to know what it maxes out at and where does it hold when the pumps turn off.

Customer: replied 1 year ago.
Ok looks to me like there is test port on the left hand side of the motor. And 2 on the right. 1 upper an 1 lower. I'm standing at the rear of the motor looking at it. Now sure which one you want me to check.
Expert:  Charles replied 1 year ago.

It should be the lower one on the fuel rail. the hose coming from the back of it, should go to the VST ,fuel pumps, or the left of the engine.

Customer: replied 1 year ago.
Gotcha. Will get a higher reading pressure gauge and check it tommorow. If we can't fix it this way. I'll bring it to you. This thing driving me nuts. Lol.
Expert:  Charles replied 1 year ago.

The 60 PSI gauge is fine for this test.

Customer: replied 1 year ago.
Valve on top right in picture pumps to 50 with switch on and bleeds to 16. Valve on bottom left had no pressure anytime. Pumping bulb or switch on. Valve on left pumps to 30. Bleeds down to 16.
Customer: replied 1 year ago.
Hey it's Ken. In Kentucky. Was this what you wanted to no.
Expert:  Charles replied 1 year ago.

No, the one on the fuel rail that the hose in this pic runs to.

Expert:  Charles replied 1 year ago.

The upper test port on the fuel rail.

Customer: replied 1 year ago.
Yea. Fuel pump on it pumps to 50. Turn fuel pump off it goes down to 16. And holds.
Customer: replied 1 year ago.
Ok. Gotcha. When you pump up bulb till hard. Then turn on ignition. It goes to 50. When you turn ignition off it drops to 16. And stays.
Expert:  Charles replied 1 year ago.

Great, volume test is good. What is the pressure reading at the back of the VST?

Customer: replied 1 year ago.
It went to 30. And fell off to 16.
Expert:  Charles replied 1 year ago.

Did you look inside the chamber for the low pressure filter yet for any debris?

Customer: replied 1 year ago.
No. Had to work late. And it got dark on me. Do those pressures look ok to you.
Expert:  Charles replied 1 year ago.

Yes, pressures look good.

If you cranked the engine for a minute with the water hose connected to it. Then pressed in on the air test port on the fuel rail. Do you get any liquid at all out of it?

Customer: replied 1 year ago.
Did that last night. Squirted a little gas on me
Expert:  Charles replied 1 year ago.

Out of the bottom test port on the fuel rail??

Customer: replied 1 year ago.
Yea I think there to. Best I can remember. When it was running.
Expert:  Charles replied 1 year ago.

You can do it after cranking the engine a few times with the water connected.

Customer: replied 1 year ago.
I'll check. Give me a minute.
Expert:  Charles replied 1 year ago.

Great.

Customer: replied 1 year ago.
Just a little mist.
Expert:  Charles replied 1 year ago.

Fuel smell or water?

Customer: replied 1 year ago.
Well I don't have a real prominent smell of gas on my fingers from pushing the valve in like I would think. Little gas. But didn't seem to be that strong.
Expert:  Charles replied 1 year ago.

thats good. not supposed to be any fuel there.

Look at the front of the VST. The pulse pump is there. Remove the hose from the front of it. then remove the two blots that hold it to the housing. Rotate the pump slightly, use the primer bulb and see if there are any leaks from the front elbow or from the hole in the back of the pump.

Customer: replied 1 year ago.
Ok. Dark on me now. Will try later.
Expert:  Charles replied 1 year ago.

Alright. Talk to you tomorrow.

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