Lost power in Evinrude

[brute29]

I have a 95 Evinrude 90HP 2-stroke. I have lost my top end power. When I push the throttle to max power it jumps to 3800 rpm then falls to 34-3500 rpm. It used to run at 4500 rpm at full throttle. I can't even come close to getting up on plane now.

I have replaced all the sparks plugs, checked the spark on each cylinder, replaced the water separator, replaced the fuel filter. Any ideas as to what my problem could be? Is my power pack going out? Do I have water in my fuel? Some other fuel issue?

Thanks for all your help in advance.

 

[wilde1j]

Re: Lost power in Evinrude

Probably dirty carbs, but do some testing to eliminate fuel system issues. i.e test fuel pump outlet pressure.
. air leak on pump suction side (bad clamp, cracked hose, cracked tank pickup tube, etc., etc.)
. malfunctioning anti-siphon valve
. plugged tank vent
. trash blocking tank pickup screen
. plugged fuel filter
. collapsed fuel line

BTW, 4500 is not where your motor should run ... it should be up ~ 5500 @ WOT.

 

[brute29]

Re: Lost power in Evinrude

Wilde1j, Thanks for the help. I believe I will take the boat into a mechanic to have the carburators checked out. I am just afraid I will mess something up worse than it already is.

I have suspected I'm not getting max RPMs out of the motor, the previous owner had a tape mark at 5500. I will have the mechanic look at this also.

Again, thanks for your help.