Temp guage 2qm20 yanmar

[01kiwijohn]

looks like you found it and it appears to be a raw water cooled alright. There may not be a thermostat, on some of those older engines, but aim for an operating temp of a little less than 140 deg. F.
Run some Salt Away thru it once in a while, to minimize internal clogging.

[01kiwijohn]

Oh my goodness, what are all those wire nuts doing in there?? While you're under the hood, fix that too.

[Old Swampy]

I have a 2GM20F (freshwater cooled). The manual doesn't say anything about zincs. I was assured by someone that this engine does not have them. Help guys; where are they, and what do they look like?

[01kiwijohn]

they don't. quite normal

[sailinbob1]

Originally Posted by 01kiwijohn

Oh my goodness, what are all those wire nuts doing in there?? While you're under the hood, fix that too.

Lol.... I'm refitting the entire boat. I've ordered a new paneltropics electrical distribution panel, and am adding a bunch of electronics. One thing at a time. She's a mess. I don't even want to go into the carpentry work,and,if you think the wire nuts are bad,you should see the battery box! I'm just one guy,and I work,so I pick a project I can tackle, depending on it's priority,in the operation of the boat. The old if it ain't broke approach. I'll be hauling her out this summer, and I'll deal with all the electrical them,but thanks for your input.

[sailinbob1]

They are on the top of the engine. You'll see a plate with 5 bolts. One at each corner,and one dead center. Forward, and after. Can't speak too the freshwater cooled.

[sailinbob1]

Well,I ended up at Advanced Auto,and bought a Bosh water temperature guage, that came with several adapters. First try, and water everywhere! Lol.... Thought that fitting went in a little to easily. Found the proper adapter, thank heaven,and (oh joy!) now I have an operating temperature guage. Only registers 120º,on a 250º guage, but an earlier contributor suggested it shouldn't run over 140º,so, I figure , I'm golden. It was where I thought, just above the alternator, on the plate housing the forward engine zink. In case anyone wants to know. Won't go into the trials and tribulations,but it was a bit of an adventure.

[sailinbob1]