Marine Trader 44 Exhaust Hose

Hello fellow trawler owners,

About six months ago I bought my first trawler. It’s a 1979 Marine Trader 44’ tri-cabin with original twin Ford Lehman 120 engines. This weekend I’m working on repairing one of a few items that were discovered during the engine survey. The surveyor found the port engine exhaust hose is showing signs of deterioration. This hose is 3-1/2” ID at the engine exhaust neck and 3” ID at the water lock muffler inlet. Does anyone know if this tapered type hose is typical of other MT trawlers? My internet searches resulted in finding only straight exhaust hoses. Is this hose still available or am I looking for a work around for this repair? Thank you for any feedback or advice.

Buy a centek fiberglass reducer.

https://www.fisheriessupply.com/centek-reducer-couplings

Mine go to a 90° fibreglass elbow then to the water lifts. The elbow reduces from 3.5" to 3".

T-Bolt Clamps in ss would be useful over traditional hose clamps for this application.

While looking at the various Centek fiberglass products I read through the Vernalift muffler data sheet. It says the typical exhaust size for 101hp - 125hp engines is 3.5” to 5”. Mine are 3” in and out. I’m going to contact Centek for their support to determine proper size.

All the convertional hose clamps will be replaced with the superior T-bolt clamps.

The exhaust elbow controls the diameter. For Lehman 120's it's 31/2"
The mufflers should also be 3 1/2" but at some point a PO cheaped out and installed 3".
If engines are running OK I wouldn't worry about it. The less back pressure the better but Lehmans aren't exactly high revving engines

If the hoses are at end of life then I would install the correct mufflers.

SoWhat said:

The exhaust elbow controls the diameter. For Lehman 120's it's 31/2"...

Click to expand...

When I replaced mine there were 2 sizes available. As you said,3 1/2", and the other I think was 3"(could have been 4" but don`t think so). Best replace like with like.