Nylon vs. Brass

[nab101eg]

I have a Malibu Wakesetter 247 with the Indmar Hammerhead 383 in it. I had problems several weekends ago with the melting of the nylon fittings that connect the water intake hoses to the manifold (temp gauge never showed overheating) . A boat mechanic replaced the nylon fittings with brass fittings; however, this makes me nervous as I am thinking that there may be a reason that the fittings are nylon. Any advice is appreciated. Thanks

[G-Mack]

see the latest discussion directly below yours... similar??

Edited August 1, 2011 by G-Mack

[nab101eg]

see the latest discussion directly below yours... similar??

yes. sounds the same. but no one is commenting on whether brass has any pitfalls.

[Pistol Pete]

According to Bakes...

Replacing these fittings with brass with cause the area around the fitting to act like a zinc because of the metallurgic difference.

[nab101eg]

According to Bakes...

What the heck does that mean?

[martinarcher]

Means different metals don't play nice together and your manifold will loose the fight. It will corrode the threads around the brass fitting. I would remove it pronto.

No way i would put brass fittings in my new Stainless Marine aluminum manifolds!

Edited August 9, 2011 by martinarcher

[SmoothWaterMan]

Is the CAT exhaust not aluminum? I think it'll be just fine, and, if water is not constantly streaming, it will not melt out like the nylon does, which has negative effects on the manifold.

Peter

[Manga Boats]

Indmar fitted brass at the factory on all 2010 + EX-Cats...

[nab101eg]

Indmar fitted brass at the factory on all 2010 + EX-Cats...

Well...I just got bad news. Brief recap: bought a 2008 Wakesetter 247 with about 160 hrs on it. Nice clean boat. I have put about 30 hrs on it. I had a problem with the nylon fittings melting...went through 3 in about 6 hrs...took the boat to dealership to determine why they were melting. They replaced with brass and said I should be good to go. Ran fine for 5-7 hrs, then shut down. Took back to dealership. They just called and said that both manifolds are cracked ARGH!!. I do not think that replacing the fittings with brass caused the problem; however, it seems like the heat problem is related. I am worried about replacing the mainfolds and then having future problems...in other words, repairing the damage without repairing the problem. Any suggestions ? THANKS

[Manga Boats]

Sorry to hear that I just warned another member about this issue on this thread and there is some info there on other things that Indmar changed to help avoid this problem. If you have the closed cooled engine with a heat exchanger PM me a picture of the engine looking down from the top and include the heat exchanger in the photo.

[Woodski]

For aluminum exhaust manifolds I would recommend aluminum fittings, a little teflon tape and they will last for hundreds of hours. Also, with aluminum manifolds install a zinc electrode as the sacrificial lamb in the system. I have seen some plastic elbow melting issues on CAT equipped boats.

[martinarcher]

For aluminum exhaust manifolds I would recommend aluminum fittings, a little teflon tape and they will last for hundreds of hours. Also, with aluminum manifolds install a zinc electrode as the sacrificial lamb in the system. I have seen some plastic elbow melting issues on CAT equipped boats.

I kicked around the idea of a zinc plug, but never installed one on my mani's, where did you get yours?

[nab101eg]

I kicked around the idea of a zinc plug, but never installed one on my mani's, where did you get yours?

Manga - I do not have "the closed cooled engine with a heat exchanger"...according to the dealership where my boat is.