NL genny issue

[MikeP]

Yesterday I received an email and a pic from a good friend who has a 53MY and an NL M844k 16 KW genny (same one that is on our boat).

I have no permission from him to copy his post or use the pic he sent but I thought it was really good info so I figured it would be good info to be here.

He was performing routine maint on the genny heat exchanger and, in removing the cast iron "elbow" from the HE that the ext hose attaches to, the elbow literally broke apart in his hands. The genny has 1800 hours on it. He called the company and asked if they had had problems with these elbows. Their response was that they did not but it wasn't unusual because "those elbows sit in saltwater all the time." They further stated that they have changed that elbow from cast iron to SS (sort of indicates to me that it WAS/IS a problem!) and that the new elbow is available for $265.

Anyway, the pic he sent showed the elbow in several pieces.

I pulled/cleaned the HE on my genny late last year but did not examine the elbow. As soon as I get back to the boat in mid Aug, it will be the first thing I seriously inspect. In fact, I am seriously thinking of ordering the SS elbow ($265) and replacing the CI elbow as a preventive measure without any inspection at all...

The M844k 16KW was replaced by a newer model a year or two ago. I ASSUME that all the current NL gennys have SS elbows but I don't know that...

 

[Mike36c]

I ran mine (NL 9kw) for three years then replaced the elbow with the SS version just for peace of mind. It's sad such a nice generator comes with a cast iron exhaust.

 

[captddis]

The elbow problem is common on the NL's. They usually split. The new elbow is Stainless.

 

[krush]

Everybody makes a mistake once in a while.

 

[MikeP]

"Everybody makes a mistake once in a while"

I suppose.. but making a genny for marine use is not really new technology and one would think they had learned about all there is to know about proper materials, etc. Then again, people like Pascoe recommend that cast iron exhaust risers on gas engines used in salt water be replaced every 5 years to avoid failure. I guess it's the same thing though I had never heard anything about NL gennys re that until I received the email yesterday.

 

[RT46]

I have an onan that has a similar sounding elbow.

I recently had a coolant leak from this elbow.
After changing numerous hoses and clamps and following drips for days I found the leak to be coming from the elbow.
The onan elbow is made out of what appears to be rolled alum and the leak was at the seam under the paint and was seeping out and dripping into the hose and clamp.

After searching for the part number and getting an ETA on the new part, I made an elbow from bronze threaded pipe and a 90* bronze elbow. No more leaks.....

 

[Avenger]

Wasn't there a big issue several years ago on gasoline generators over a carbon monoxide problem caused by iron plumbing in the exhaust? I think it was Koehler.

 

[captddis]

Wasn't there a big issue several years ago on gasoline generators over a carbon monoxide problem caused by iron plumbing in the exhaust? I think it was Koehler.

Yes it was galvanized pipe nipples.