73 evinrude 135 hp not taking in water to cool

Finally got the 73 evinrude 135 hp engine overhauled.

I have to break it in, but I can only run it for 5 minutes before its temp gets way too hot. The water is not cycling through.

I made sure the key was good, impeller is new, made sure the plastic sleeves to the tubes were connected in lower unit.

I did tap into the #1 cylinder to create a tell-tale, learning how to do that on iboats. (there is no stream)

The only way i get water is if I put on the muffs and apply pressure with my hands holding them there, then water cycles through and the engine is cooling.

What should I be looking for to do or fix?

thanks for any input or help,

Matt

Re: 73 evinrude 135 hp not taking in water to cool

Is it possible any of plumbing came loose when you put the LU back on? Or maybe there is some debris in the tubes blocking the water?

Do you have a thermostat....and is it working?

Re: 73 evinrude 135 hp not taking in water to cool

Whip the lower unit off again and check if the water pump is actually pumping water. Spin manually with a drill in a body of water. Are you sure the water tube is properly aligned ?? Post results.

Re: 73 evinrude 135 hp not taking in water to cool

Is this problem when boat is launched or engine in a 'barrel', or just on muffs?

Re: 73 evinrude 135 hp not taking in water to cool

A strong telltale usually indicates the water pump is working well in the lower unit. No telltale indicates either that the pump is not working or that the telltale is plugged. The pump could be pumping and the telltale could be plugged. Secondary issue: You did not mention that you had replaced the vernatherm (thermostat). If the statvernatherm is stuck shut, cooling water will not be able to pass through the powerhead and it will quickly overheat at idle. Did you replace just the impeller or did you put a whole impeller kit in (439140- including the housing?) What temperature do you consider "too hot?" Does the hot horn go offin the control box, or are you measuring with a laser temp gun?