40 HP overheat

[walter lowe]

the pump on my 1990 40 Hp yamaha stopped spitting water but the engine still ran fine. i got a water pump kit and replaced all the parts. the old parts still looked like new. now the engine spits water, but at full throttle it overheats (warning light and power loss) within 5 seconds. it didnt do this before. the only thing that was questionable in the repair was a small hose attatched to the front of the lower unit. only 1 end was attatched to the lower unit and the other end of the hose isn't attatched to anything. i dont know if this ha anything to do with the overheating cause water is streaming out the back. please help if possible.
walter-

[jb123]

i assume thats your speedo hose and wont affect the heat.
was your old impeller in pieces when you changed it out? if so you may have fragments in your water tube.
secondly, if you have thermostats, change them out if theyre over a year old.
did you do the complete waterpump kit? including the housing?
it will idle and mid range fine but heats up at high end?
lastly you may have to remove your water jacket and clean that out.

[walter lowe]

thanks for the speedy reply. it only heats up at high rpm. could run all day at low and mid. the old impeller was in great condition. i did replace everything but the main pump housing. wasnt included in the kit, but the old one looks good. all gaskets and metal impeller housing cylinder were replaced. i checked the water exit hose and its clear. it spits warm water but i noticed that wheb i run it at high rpm and it loses power, it stops spitting water till i kill it and restart. i dont think i have thermosats. whats / wheres the water jacket?

-walter