Thermostat source

[sailr4]

Please help. I going crazy.  Every time I think I found a vendor/part number for a 160 F thermostat for my 25XP, it says its 180 or doesn't say.  I know it probably doesn't matter too much, but I sail in the warm waters of the Chesapeake, so I'd like to stay cooler. Anyone bought a thermostat lately? Would rather not pay $60 to Universal.  By the way, the reason I need a thermostat is because my boat did not have one.  Go figure.

Rob

[KWKloeber]

Rob

A 160F tstat for the XP is:
   Kubota thermostat 160F 71C      1E399-73010   $28
   (supersedes p/ns 19203-73010, 19203-73013, 19203-73014.)

See the service bulletins, the KB tsat likely won't have a bypass hole, so drill a 1/8" hole, or two, thru the inside edge of its flange so there is a constant coolant flow thru the exhaust manifold when the tstat is closed.

Which tstat to use is based on the water type, not it's temperature. So I'm not following your reasoning on which tstat you want to use?

Ken

[sailr4]

Thanks Ken. That's the number I was looking at, but no one had specs on it.  I was reading that people in colder waters were using the 180.  I really had no other basis on my reasoning, except the 160 was the OEM.

Rob

[KWKloeber]

rob

It was somewhat of a loaded question.  You want to use a lower temp thermostat not because of the sea temperature, but because it contains certain salts.   But, a diesel runs happier at higher temps, so if on a freshwater lake or river you use a higher temp thermostat.

Certain salts in seawater become less soluble as the water temp rises (at least in the range of temps in which our engines operate.)  Strange, because we know that table salt (sodium chloride) dissolves easier in hot water than in cold.  But, for instance, so does sodium sulfate -- but above 50 C (122 F) its solubility decreases.  So to lessen the opportunity for salts to precipitate out, a lower thermostat is installed to keep the engine coolant a little cooler, which keeps the seawater cooler.  This is a particular problem in seawater-cooled engines, like the original Atomic 4 because salt deposits would build up and block internal engine cooling passageways.  So that had a 140 F thermostat.

k

[Mark Sutherland]

I've always bought my 160 thermostats at Torreson marine for years.

[womble]

I got mine from kbrosusa on ebay. $16.99.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p3984.m570.l1313.TR0.TRC0.H0.X181667007547.TRS2&_nkw=181667007547&_sacat=0

[KWKloeber]

W:

What temp is stamped on it?  The description for that part number comes back as a 180* F, not 160* F thermostat.

Kk

[KWKloeber]

Confirmed.  That Tstat is 180*F. 
YBYC, but shouldn't be used unless u r in fresh water.

kk

[womble]

KK. Thanks for checking on this.

I bought it as a spare. My engine never gets above 160 anyway.

But to the OP's question that basically remains unanswered, where is a reliable source for this part?

Amazon has it https://www.amazon.com/Generic-KUBOTA-THERMOSTAT-ASSY-1E399-73010/dp/B07B885ZRT/ref=sr_1_1?ie=UTF8&qid=1521477884&sr=8-1&keywords=1E399-73010 for $28.95 plus $5.49 shipping. (Not Prime)

[KWKloeber]

Asked and answered; read posts below....

[sailr4]

I ended up getting a pretty good deal from lawneq.com

https://www.lawneq.com/kubota-part-assy-thermostat-1e399-73010.html

Rob

[KWKloeber]

Yep,that's less than Kubota dealer retail.

Did it have the temp stamped on it?
Did it have the bypass hole drilled in the flange?

k

[Stu Jackson]

http://c34.org/bbs/index.php/topic,3133.msg17419.html#msg17419

[KWKloeber]

Stu

Fake news! The correct p/n has changed for both.

160F Kubota p/n 1E399-73010
http://c34.org/bbs/index.php/topic,9793.msg74510.html#msg74510

180F kubota p/n 15531-73014. 

k

[Gregory M]

Ken
I have M35, which is V 1200 (correct?) , would the thermostat p/n be the same as for 25's.