Universal Diesel M-18 Exhaust Riser Problem

[Jim Branch]

The original Universal M-18 exhaust riser is made of steel and wrapped with an asbestos-like material. The riser has a sump, which I presume is designed to drain the exhaust system in freezing weather. Raw water remains in this sump at all times. Leaks are difficult to detect due to the wrapping. Mine corroded and the sump ultimately rusted through while motoring, sending raw water into the bilge and partially burnt exhaust/fuel/water vapor into the engine's air intake. Although I shut the engine down quickly upon realizing the problem, the foul air caused the number one intake valve to stick and the push rod to bend. I have a new stainless steel riser fabricated by a machine shop (without a sump as I live in Florida). I recommend a careful inspection of the riser sump - unwrap it if necessary.

 

[Gordon Torresen]

S/S exhaust

Don't let that stainless steel exhaust keep you from checking it occasionally. Some of the combustion products attack stainless faster than iron. You may have to replace it in a shorter time than the original. The best is schedule 80 black pipe. You don't even want galvanized pipe because of the gasses put out by the galvanize when it gets very hot.

 

[Steve W.]

rebuilt my entire M-18 exhaust for about $20.00...

with pipe from Home Depot. Original lasted 14 years. Works great after 25 hours, no leaks, etc.