250 E-Tec--Dies at upper RPM

My partner bought a like new 21X Triton with a 2005 model 250 E-tec.. The boat was bought new by a gentelman who used it about a half dozen times. Then had some health issues..
It came with a 24 Raker.. we took it to the lake and were only able to get 53 mph out of it.
We raised the mtr as high as it would go on the 8" manual j-plate and picked up 10 mph. but it would start walking at 55.. Changed to a 4 blade power tech 24 pitch-- gained another 4 mph and much easier to drive.,

However- later in the day the mtr died while running about 55.. It would not re-fire-- the gas bulb was soft --after many squezies it got hard and the mtr started and ran ok----only to do the same thing after several short runs later!!!!!!

Was thinking about changing the fuel lines and the fuel filter-------------However there are many specialized fuel lines on the mtr...
Do these need changed due to the ethanol degredation-- or are they OK ???
I have heard of several issues with older fuel line vs ethanol http://www.bassboatcentral.com/smileys/sick.gif
We also found a kink in the fuel line where the jake leg who rigged it did some chitty work http://xs-s.com/zf/images/smile/emthdown.gif not sure if it is enough to starve the engine for fuel or not!!

Any ideas--help--solutions would be welcome http://www.bassboatcentral.com/smileys/thumbsup2.gif

Hooking up a vacuum gauge a piece of clear fuel line to the pump inlet will show if there is a fuel restriction or air bubbles in the fuel system causing the motor to quit at high speed.

Thanks http://www.bassboatcentral.com/smileys/thumbsup2.gif