new to this boat

[dale1]

greetings. I just bought my first real boat. 2000, carolina skiff, sea chaser, 21' with a 150 yamaha 2stroke. If it idles more than 2 min, the overheat alarm goes off. My friend and i changed the water pump today. the old pump was in good shape. it did not fix the problem. any help greatfully appreciated. wife is not happy with me. :redface:

 

[produceguy]

Re: new to this boat

You might try posting in the right forum.
Not sure if this is an i/o , mine did that, changed the impeller, she ran great.

 

[rlb9844]

Re: new to this boat

You might try the thermostats. How long has it set up before you bought it?

 

[dale1]

Re: new to this boat

You might try the thermostats. How long has it set up before you bought it?

sorry i posted in the wrong spot. It's my first post here. dont know how to change it yet.

I pulled the thermostat housings off and found the stats removed??? more confused now?

 

[Home Cookin']

Re: new to this boat

post in Yamaha forum. but replace thermostats.
Can you tell if it's really overheating? Is the block hot? tell tale working? An overheat at idle with a tell tale working is probably a problem with the alarm itself.

 

[99yam40]

Re: new to this boat

install new thermostats and pull and clean PRV. Replace parts as necessary.

A PRV that is stuck open will dump too much water at low RPMs, causing the block to not fill completely and overheat where there is no water in contact.
Without thermostats, the water does not circulate properly through out the motor causing hot spots.

If all this does not fix it then you could have head gasket problems of cooling passages scaling up /blockage.

You did not say if this motor is just overheating at low RPM and not high, or all the time.

 

[dale1]

Re: new to this boat

update. the boat is used in salt water. today i took it to a fresh water lake. no alarm sounds. runs great. i did not let it idle long. about 2 or 3 minutes. How long should it be able to idle? If it's scaling in the motor, how is that fixed? where is the PRV? thanks for all the help. wife is better today:facepalm: