Maybe Rodbolt can help me he sounds pretty sharp!!

[huntingsidekick1]

Hello,i have a 87 yamaha 150 2 stroke that i just purchased.What a nightmare!!! This thing will run great for 5 minutes with the muffs on and then i get a solid buzzer sounding and the engine will idle fine but when you try to rev it up it breaks up bad and will not rev up.Let it set about 30 minutes and runs great again for around 4 to 5 minutes and starts buzzing and engine act`s the same.The engine still smokes so i asume it`s still oiling.This is a four winns boat and has a red and green light on each side of a oil can in the tach.when it does this the red light comes on but the tank is full.I also noticed the water coming out of the pisser was not warm,so i checked the thermostats and they were crusted with salt.I cleaned the stat housing and replaced the stats but still dont seem to get warm.I also checked the pressure valve and cleaned it up to but still not warm.Could it be that the engine isn`t running long enough to get warm.Any idea`s would be GREATLY appreciated.Thanks not sure if it`s a oil or water problem that`s setting off the alarm? Or anyone who could help with this problem.

[marinermikes]

You are overheating. When the buzzer goes off it also puts the engine in slow mode. When in slow mode they do run rough. You need to find out what's making it over heat. You have a thermstat or popit valve not opening.

[jb123]

new to you............do yourself a favor and replace waterpump with housing, stats AND PRV, then repost...

[huntingsidekick1]

175 yamaha

Thanks guy`s i will get the parts tommorow and try it.If i can find them.Thanks again i relly do appreciate the help.!!!!!!!

[BaileysBoat]

When the buzzer sounds it can indicate low oil level or overheat. You need to figure out which. An overheat or low oil warning causes the engine to run in limp in mode. This limits RPM to 2000 or less.

If you have a red oil light when the condition occurs (as you descibed in your post) I would start by diagnosing the oil warning circuit. The tank might be full but could be a bad sensor. You need to disgnose the warning circuit before you throw parts at it.

[jb123]

he has a 24 year old motor which he has no idea when any parts were changed.....i say replace EVERYthing that is general maintenance, but to each their own