25 evinrude can’t get up to speed

[Tpainter81]

I have a 1982 evinrude 25 hp electric and manual start. I was cruising the other day in Jon boat about 3/4 throttle since there was some chop. I then sped back up to wot for a minute. Then it just lost speed. I could only go about 5 mph maybe. Motor starts instant runs perfect at idle. Good spark on the plugs. I was also having shifting problems. I could not always get it into forward gear very well. I adjusted the rods as much as I could. I decided to take lower unit a drain. It was full of water. Only second time I’d had it out ever but since I changed oil in lower unit. I then decided to inspect the gears. Nothing real bad from what I could see at first. I did notice on the inside of the gear closest to the prop the ears the clutch dog hits to activate that gear were severely worn down. I know that would cause the shifting issue but would that cause loss of speed? Or did I spin my hub in my prop possibly. I’m at a loss here fellas. Any ideas would be great. I am probably going to replace lower unit and prop anyway but I would like peace of mind

 

[F_R]

If it has a spun prop hub, the motor will race at high RPM but not push the boat fast.

The gear closest to the prop is the reverse gear.

 

[Tpainter81]

It does seem seem to be turning high rpms. It’s not spitting or sputtering either. Runs smooth as can be no smoke starts instant without choke. Carb was just rebuilt and brand new tank, hose and fuel bulb. I can foresee it being a fuel issue. Lower unit was beat up a little when I acquired the motor. Looks to be jb weld on it and anti cavitation plate has a chunk broke off so I was planning on replacing the whole thing anyway. I just want some confidence that this will fix it.

 

[Tpainter81]

That’s supposed to say it does not seem to be running high rpms. Sorry

 

[oldboat1]

Check the remote throttle cable. Disconnect at engine and insure the linkage on the engine advances to WOT. If so, look for an issue with the remote cable or box.