'rude 40hp thermostat faulty?

[rudeafrican]

Hi folks,<br />Is there any test to perform on a thermostat to check for functionality? I've just removed the thermostat (part # 433378) on both my 1990 40hp 'rudes and found the following: when cold I can blow air through it from 1 side to the other. When dropped in boiling water for a while, nothing changes. This is on both. I presume they are both faulty? The motors both battle to idle when cold.<br /><br />Thanks.

 

[DJ]

Re: 'rude 40hp thermostat faulty?

Rude,<br /><br />Typically, if they're stuck closed. It will overheat. Yours may be stuck open-can't see em'.<br /><br />Won't hurt to replace both on an engine of that age.