Evinrude 65HP loss of WOT

[Uniflite32]

I have a 1973 65 HP Evinrude that ran fine when I used it in June. WOT was 5300. I took the boat out on Sunday and it started and idled fine but was sluggish to get on plane and maxed out at only 4000 RPM. The bottom is clean etc. Nothing has been changed since the last time out.
I replaced the spark plugs, new fuel, fuel water separator and fuel line and ran it again a few hours ago with no change. The engine runs smoothly, it does not miss. It just won't spool up to full RPM and is very slow to get to 4000. I'm not a mechanic but hope there is a simple place to start. The carbs were rebuilt in 2006. Does this sound like a fuel pump? Thanks!

 

[jtexas]

Re: Evinrude 65HP loss of WOT

classic symptom of clogged hi-speed jets. most common cause of clogged hi-speed jets: inactivity. motor sits for 2, 3, 4 months, gas turns to varnish. Next most common cause: contaminated fuel. Still using the original metal 6-gal tank came with the motor? it's probably got little particles of rust in it. You might want to try pumping the primer bulb while its bogging, if it improves performance, rebuild the fuel pump. But my money's on carbs.

But, first, check the compression - no since throwing money at a motor with bad compression.