Water pump trouble 2004 60 hp

"I have a 2004 60hp efi bigfoot. At idle and up to about half throttle it pumps water out the discharge line, but at full throttle it doesn't pump any. It's a new impeller, housing is in good condition. Any ideas, or pointers."

It's almost preferred if you put your engine model number on posts, if you have it. Too many engine variances to help without engine specifics.

Not sure if your engine has a pressure relief valve on the crankcase? If it does it may be sticking open, which is allowing most of the water to bypass the cooling at higher rpms and makes the pee tube stop showing water.
Just a wild guess.

Couple of questions -

firstly, we are talking about a 4 stroke, 60 bigfoot - correct??

second, is the guardian system kicking in (restricting rpms) because it's detecting an overheat?

You say "new impeller" and housing is in good condition. What about all the gaskets and seals??? Were any replaced or just the impeller?

I lived in Gander for a number of years and know that season to season you experience some temperature extremes. These are hard on the seals and they may be leaking when you are asking the waterpump for "more pressure"...

You're responding to a post that is 2.5 yrs. old.

Didn't even notice that - saw the response from (trynhooker)...

You aren't the first or the last...just keep up the excellent contributions you provide.

Same right back at ya...