60 Yamaha power loss at higher rpm

[jsnhall]

My 2000 60 Yamaha starts fine and runs fine up to 1/2 to 3/4 throttle. If I push it up higher it will run good for a minute or so before it runs really rough and losses power and I have to idle a few minutes before I can plane out again. It only runs poorly if I go too fast. No alarm is going off. Does this engine have an overheat sensor to shut down some cylinders if it's too hot. Water is streaming out of the side hole and coming out of the exhaust ports but I did notice a dribble of warm water running down the side of the lower unit the other day. I can't see any leaks with the cowling off. I'm thinking there's a leak somewhere and this is a cooling problem. Any suggestions?

 

[rodbolt]

Re: 60 Yamaha power loss at higher rpm

have you physically tested the horn to see if it actually works?<br /> yes the overheat will trigger a RPM reduction, so will an oil alarm. once you verify the horn works start looking at fuel and fuel restrictions.

 

[jsnhall]

Re: 60 Yamaha power loss at higher rpm

Gotta be a cooling thing then. I've already been through the fuel system.

 

[andy6374]

Re: 60 Yamaha power loss at higher rpm

You said you've been throught fuel system...what did you check and/or replace? What type of maintenance has been performed on the fuel system (i.e. the fuel pump, carbs, fuel lines, primer bulb). How do the spark plugs look?<br /><br />When was the last time you had the water pump or tstats changed out? Do you have a water pressure gauge installed? Have you check the oil lines for cracks or air leaks?

 

[andy6374]

Re: 60 Yamaha power loss at higher rpm

If this isn't a carbed model, my bad.

 

[jsnhall]

Re: 60 Yamaha power loss at higher rpm

It is a carbed model. I checked the fuel lines and the fuel pump and all that stuff. I only things I've ever replaced are the spark plugs. That's the first thing I did. I've never done a water pump, impeller, or tstat on a outboard and that's what I'm leaning toward. thanks

 

[baymaster 2150]

Re: 60 Yamaha power loss at higher rpm

In my past expirence, water steaming out of the pee hole is an indication of no water getting up to cool. I replaced my water pump once when it was doing that and it started peeing fine thereafter. Sometimes, if you run in shallow, it picks up mud or grass and can cause it to pump that through your block. Try blowing it out through the pee hole with compressed air under 30 psi's. Good Luck

 

[K7STW]

Re: 60 Yamaha power loss at higher rpm

Baymaster - I think he said STREAMING - not STEAMING<br /><br />Just trying to help

 

[jsnhall]

Re: 60 Yamaha power loss at higher rpm

Running great once again! It was running in rpm reduction mode. Changed the water pump and thermostat and it's fixed.