No top end power

SmokyMtnGrady

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How old are the fuel lines? I have never had twins in my life. Are there two pick ups ,one for each motor? I would assume right ? maybe it's in the tank where the pick up has some debris in it? Seasick is spot on ,it sounds very much a fuel starvation issue.
 

seasick

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Two pickups in each tank.
You did get me thinking that a somewhat simple test is to swap the fuel lines at the output side of the water/separator and see if the problems switches engines. I don't think it will but it it does that narrows the fuel issue to the original filter and everything back to the tank, pickup, maybe anti-siphon and any tank valve if there is one. If it is not easy to swap hoses at the filters, swap hoses at the output side of the primer bulb ( probably a lot easier to get to) That will test all the items I mentioned plus the actual fuel line from the separator filter and the primer bulbs.
 
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SmokyMtnGrady

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Two pickups in each tank.
You did get me thinking that a somewhat simple test is to swap the fuel lines at the output side of the water/separator and see if the problems switches engines. I don't think it will but it it does that narrows the fuel issue to the original filter and everything back to the tank, pickup, maybe anti-siphon and any tank valve if there is one. If it is not easy to swap hoses at the filters, swap hoses at the output side of the primer bulb ( probably a lot easier to get to) That will test all the items I mentioned plus the actual fuel line from the separator filter and the primer bulbs.
In a way I would think you would hope the problem pops up on the other motor by doing this. One, it narrows the issue down and two, one would think it would be an easier and more affordable fix . it would be easier in my opinion to swap on the downstream end of the primer bulb too. Good luck I hope you figure it quickly. Report back ,inquiring minds want to know.
 

Throttle1971

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So yesterday I took the fuel tank off my Boston Whaler and connected in directly to the fuel line north of the primer ball. No change, same issue. I replaced the filter fuel filter that resides in the small bowl with red floating gasket in the very front of the engine No change, same issue. I replaced all 4 spark plugs, upon removing the old plugs all four looked just about the same No change, same issue. I traced all fuel lines in the engine and I don’t see any visible issues. I called a mechanic and he is coming tomorrow. Told him I would pay double his hourly rate to get bumped to the top of the list. I posted a photo of the auxiliary tank I connected and the throttle the throttles when port is a 4200 RPM and Starboard as at 3800 RPM. BTW- I also inspected the throttle position on one miter and compared to the other.
 

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wspitler

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I thought you said the engine filter with water warning was replaced previously? My money is still on the LP or VST filter, but you said they were "cleaned." A VST filter cannot be cleaned adequately in my opinion. Good Luck!
 
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Throttle1971

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Ok - so after all of the parts replaced- ended up the ECM and wiring harness was bad and causing lack of fuel to cylinders 1&3. Mechanic took it out and said it runs great. I am picking it up tomorrow morning and dunking it ASAP and will advise.
 

DogBone

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Ok - so after all of the parts replaced- ended up the ECM and wiring harness was bad and causing lack of fuel to cylinders 1&3. Mechanic took it out and said it runs great. I am picking it up tomorrow morning and dunking it ASAP and will advise.
Thanks for the follow up on what the problem turned out to be.
 

wspitler

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That is very unusual. Fair winds and following seas from here on!
 

seasick

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That is very unusual. Fair winds and following seas from here on!
Unusual indeed. A bad ECM and a bad harness? I wonder what could have caused that.
At least it's fixed. Have fun!
 

Throttle1971

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So I miss stated above. The ECM was fine. It was however the wiring harness and two bad injectors. Plenty of top end but the motor still runs rough and has lots of vibration. Noticeable difference when idling over the other motor on how it shakes. Any ideas?
 

Throttle1971

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So as I read more about the earlier F150 engines, I have a 2005 and a 2006 and they both do have a small whining so I was thinking about replacing both Harmonic Balancers. Recommendation on where to buy?
 

Crazyfish1

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I have a GW 232 with twin 150's. The starboard motor has no top end. The max RPM I can get is 44 and that is by throttling up and down, if I just leave it wide open I get about 38 RPM's. Here is what I have done so far. I have both engines pulling from the same tank to eliminate the fuel as an issue. I swapped the primer balls between both motors, problem not fixed. Fuel injector assembly was removed and the fuel injectors have been cleaned and replaced the very small fuel filter near the injectors. Replaced the hi and low fuel pumps. All cylinders are firing correctly and the engine idles perfectly. Any thoughts or suggestions on what to do next?
Take each plug out inspect & clean and do a compression test on every cylinder as you did the first one sounds like burned a piston. Good Luck
 

Crazyfish1

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Take each plug inspect clean &take compression test on each cylinder you may have burned a piston. Good Luck
 

Harpoon

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Fuel Pick Up In Tank ( that one can drive you crazy)
Fuel lines, sucking air, pinched, clogged, deteriorating
Water in Fuel separator
VST

Had a friend with that issue on f150's and it was throttle position sensors also
 

Bilpep

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When I list top end power on my starboard etec 200ho I checked filters fuel lines ran on external tank alk with same results.
It ended up being a fuel injector. Not cheap 580 from the dealer but runs fine now.