F115 EFI is losing high end RPM's & Power

Need help. I got a 02' F115TLRB on a pontoon, 550-hrs. I pressure washed. Ran fine the next day. Five days later I could only run 3500 RPM's @ WOT. The water float in the cup filter was half way up the cup. After emptying the water I ran Mercury injector cleaner from the dealer, new plugs, and filled the tank with 93 octane non ethanol (18-gal added with 6-gal w/ethanol left in the tank, 24-gal total).

Added more injector cleaner, stabil, and Heat ...while running the 24 gallons out on 2-hour trips over the last 3-weekends. No additional water was ever found in the cup. I've opened the cannister/float chamber drain plug 3-times and hand pumped fuel to clean out. While running on the trips I rev'd throttled up/down and occasionally was able to get upto 5200 RPM's and then it losses RPM's and power within seconds. I've added a fuel seperator last weekend. The hand pump seems softer than usual. Last run, I "rev" the throttle and can get upto 5500 RPM's and it sometimes holds for as long as 30 seconds and then losses.

Dealer says all along that if the cleaner doesn't work that the injector's need cleaned....Not replaced.

Should I give it another tank of gas with injector cleaner and wait and keep working to see if it clears? It looks like new injectors would be easy to put in (?) but would like to find & read the shop manual before I try to install. Can it be something other than the injectors?

No trailer & it's 10-miles by water to the nearest Ramp & the dealer.

Anyone have any experience with this type of trouble?

Thanks.

[reelnative]

yep been there done that , your injectors need to come out and get cleaned, its not as hard of a job as they make it sound, I can pull my injectors clean them and have them back installed in 30min, all you need to do is pull the 3 bolts holding the fuel rail 2 13mm bolts and 1 10mm, pull the fuel rail up and out of the bottom of the cowel, pull the power clips going to the injectors and then twist and rock the injectors out of the fuel rail, be sure not to damage the o rings on the injectors when installing back into the fuel rail, after they are out take some good spray carb cleaner and spray with the straw tip into the injector, what you are doing is cleaning the filter basket that is in the hole of the injector then wipe and then spray the tip of the injector, and then reinstall, if it runs great for about 20 or 30 minand then drops rpm again then you will have to change out all the filters on your motor and also pull your vst tank and clean it out, hope that helps