1974 Mercury 402 poppet valve

J Dawg

Cadet
Joined
May 29, 2016
Messages
19
I have a problem, my motor was overheated and no damage to power head except the poppet valve melted into the spring. I have looked everywhere for a replacement and can only find a thermostat. My motor is the serial group #5. Serial number 3593716. I replaced the cdi box and the lower unit and impeller. But when I was searching for blockages before impeller, opened the thermostat cover and found the melted mess. Saved spring and the rubber seal on the bottom. Everything else plastic melted. Cleaned out the block and all passages I could without tearing motor apart. Question is, running this motor without poppet installed bypasses the thermostat. Can I run it without problem? I ordered the replacement for serial group 3, but it is not the same size. Do I just run without both or can I get the right parts from somewhere else? Done some searching on this site and another site that doesn’t have available. Any info is appreciated, thank you.
 
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