Yamaha 90 2 stroke overheat at idle

[Tarpon18]

I have had trouble with motor overheating at idle or under 1000 rpms. Changed thermostat, and water pump kit, and cleaned pressure valve. It seems to not pee hard enough at low rpms, like its getting air from somewhere. On the muffs it pees fine, but water is being forced in it. What else should I check, I appreciate it. Have a busy week and dont want to cancel trips by bringing it to the shop. Thanks

[jb123]

switch out thermostats first,...was your impeller broken up, if so you may have debris in your water tube and lastly you could have clogged water jackets.

[Tarpon18]

I cleaned the telltale tube and found nothing, I also blew air through the lines. What other lines do I need to clean, is there something I missed? The old pump wasnt to bad, the fins were cupped pretty good, but not broke. Thanks.

[Aleutianwest]

I cant remember if these had a seal were the pump and water line to block go but sometimes they go bad and dont seal

[jonp]

Hi Tarpon

I have the same engine 90HP. Had a problem like this... Dove me f----g nuts. Turned out to be a piece of an old impeller in the water tube. It did pump water, just not enough then After a few minutes, the alarm... Since you use this in salt water you may want to inspect all the water passages if the water tube is not clogged up.

good luck

jon