115 4stroke mercury running issue

[Stevekfisher]

First time out new to me. I recently bought a 08 pontoon with mercury. We went out in it before we bought it ran perfect. Has sat for a few months before we took it out. I put 20 gallons fresh 100% has in it. Full throttle take off great for about a minute or two ran to 6000 planes out good with the trim. And then starting bogging. Seemed to bump the trim button up or down and it improved for a second or two. Never missed just seemed to bog. Backed off the throttle but wouldn?t run back st 6000. Never died or sputtered or missed. Just like dragging an anchor. The weird part is felt like electrical almost with the trim switch ???? Any help ?

 

[tommarvin]

We bought twin 115hp four stroke EFI, the boat sat for a long time,not sure how long is long, it just would not run, we hand pumped the old fuel out,,
Cleaned the fuel injectors installed a new fuel filter in the fuel injector, cleaned the vapor seperator tank and screen, changed the on motor fuel filter, installed a new fuel water seperator, now life is good,she runs like a beast.
If you think its electrical, check every inch of wire, and where a wire goes into a electrical connector pull the connector hard.

 

[icwingman]

Put some sea foam if its going to sit.

 

[Stevekfisher]

Tom, thanks for the input... I figured out that the day I had run it I didn't have the master power switch turned on. One guy tells me that was the problem, another guy says no it's just for accessories running the battery down. I haven't tried it again. second guy says drain the water fuel separator and see if there is water in it. I poured two bottles of Heat in the fuel tank. I tried to figure out how to drain what I thought was the water fuel separator on it today but couldn't see where to drain it. he said there should be a petcock on the bottom but I didn't find one. have you ever heard of either of these things being an issue with yours.

 

[tommarvin]

Steve, you should hand pump all the fuel out of the fuel tank.Harbor Freight tools has a cheap hand pump we used it.
Install a new fuel water separator, we use Yamaha mar-mini-if good to 115hp max.Or dump the old water separator in a glass container and look for garbage and water,fill with fresh gas spin back on.
Install new on motor fuel filter, drain the sight bowl.
remove and clean the vapor separator tank, and the screen in front of the high pressure fuel pump.
remove fuel injectors, remove the filter on end of the injector make the adapter and pulse cleaner through the injector its on you tube.Install new fuel filter on the injector.
Your fuel system is perfectly clean now.
Now if the motor doesn't run , do you have a way to read error codes.