Yanmar Diesel cooling blockage at street nipple to exhaust

bris59

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Jul 5, 2019
5
Hunter 36 Legend Houston
My yanmar diesel (27 hp, 3 cyl) for my hunter 36 has had two incidents 4 years apart where the seawater exhaust from the engine cooler Gary’s blocked at the nipple on the outlet leading to the exhaust gooseneck. These are carbon steel and i get they rust. Anyone have a more permanent solution they have done instead of keep replacing the steet nipples every few years?
 

dLj

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Mar 23, 2017
3,431
Belliure 41 Sailing back to the Chesapeake
There is a stainless replacement as an aftermarket, but I don't recall the link....

dj
 
Jan 4, 2006
6,512
Hunter 310 West Vancouver, B.C.
I take it when you say "street nipple" you are referring to a "close nipple" ?

1713668967515.png


A street fitting has a male thread (MPT) on one end and a female thread (FPT) on the other end.

1713669830775.png


Still close enough for our needs. Your carbon steel nipple can be replaced with a hex bronze or SS nipple from Groco or other marine supply store at a small fraction the price of the specified engine part price.

If I'm on the wrong track here, please post a picture of the offending nipple where it attaches to the mixing elbow and we'll ses what's available.
 
Jul 18, 2015
74
South P10 Pugetopolis
Had the same problem with my volvo penta. Found these folks on the internet. stainless wont fill up your nipple with scale.

not advertising just a happy customer
 
  • Helpful
Likes: dLj
May 29, 2018
462
Canel 25 foot Shiogama, japan
the engine cooler Gary’s blocked

No, Gary hasn't blocked anything. I promise!!!

As mentioned, in order of preference, Bronze, Stainless, Brass.
You are looking for a Barbed nipple. Either straight or as an elbow.The barb accepts the hose and the screw end screws into the exhaust.
Bronze straight

Bronze elbow.

Stainless straight.

Stainless elbow.

Brass straight


Brass elbow
 
Last edited:
Jan 11, 2014
11,470
Sabre 362 113 Fair Haven, NY
A little more information would be helpful, what model number Yanmar there are several 3 cylinder Yanmars? Can you post a photo of the part that is blocked?