Yamaha 50hp over heat issue...

[Euroski]

I'm looking to buying pontoon with 2004 Yamaha 50hp 2 stroke. Would like to add noticed issue after about 3/4 mile on water, no alarms, only surging engine rpm.

Owner had impeller replaced because of overheat and no water peeing out. All was ok for about 1 mile when peeing stopped. Shop that did impeller told him if issue returns will need to dismantle powerhead to clean out impeller remains. Estimate was $2500... my question does this sound correct and to what extent does powerhead need to be torn down?

May even consider finding a 90 or 115hp depending what I can buy it for...

thanks

[Merc 2.5]

They prob talking bout cleaning out exhaust/adapter plate under powerhead, but if it got remotely hot , the complete kit should had been replaced , idk bout a yammy. does it have poppet? If so it should b replaced and stats checked then if it does it again , start checking else where (under ph)

[Euroski]

Been trying to find water flow diagram but so far no luck.

I'm told it's the same as merc uses but painted black.

[Merc 2.5]

"Same as merc" is what I was thinkin but not sure. I'd check poppet 1st. If a piece rubber got thru it went straight to poppet, or maybe sum corrosion has it stuck or head gasket depending on the temp it reached

[Euroski]

Since this is the same as a 50hp merc, anyone have the manual to send photo of water flow?
BTW, it shows up as a 2005 50TLRD