'96 50hp Thermostat - Overheating

[Kudunk]

Model# J50DTLEDC 3 cylinder overheated last time out, running about 4100 rpms, new water pump and housing <12 months ago, good waterflow from tell tale. Pretty sure the thermostat is the issue, found assembly diagram online @ BPR.com. No problem with removing cover plate; how do you remove the diaphragm which is secured in place by metal ring? Is there a special tool or procedure? Any suggestions?

 

[bankerjohn]

Re: '96 50hp Thermostat - Overheating

The "metal ring" you refer to is described in the parts diagram simply as a "washer" ... can you tell if it's just a flat washer? If so, it should just "pop" out unless it's "embedded" in the diaphragm.

Is the diaphragm made of rubber? If so, is it fitted in a groove in the cylinder head?

Someone who has the same motor would probably be able to answer your question better than me ... or maybe a close-up photo would help!

 

[Kudunk]

Re: '96 50hp Thermostat - Overheating

Fixed it, just tugged it a bit harder, popped out. Really packed with debris, cleaned, flushed engine, re-assembled. Expect it will be fine.

Thanks for the reply!