Unlike the original equipment part, we have the type 316 stainless steel riser electropolished after welding. All additional stainless fittings (elbows etc.) are also electropolished. Electropolishing (often described as the reverse of electroplating) passivates the metal by removing the ferrous metal from both the inside and outside surfaces of the tube. This is especially important at the welds where the welding process disturbs the metal structure and makes it more susceptible to rust and corrosion.
This riser replaces early units that incorporated a heavy casting as the water injection fitting (for reference see the red part in the photo below under More Images). This casting had a 1-7/8" OD outlet for connecting the hump hose. We have matched the outlet outside diameter, tested the 2" hump hose, and found these two to be a good match.
The only way to remove the exhaust riser from the boat is to remove the exhaust flange from the engine. This dictates that, at a minimum, you will need to replace the gasket. Most customers report the exhaust flange is impossible to remove from the old riser. The male thread on the end of the riser is typically seized to the female thread of the exhaust flange. If this is true for your parts, you will need a new exhaust flange too. Both are available below under "May we also suggest" below.
Always install a hump hose between the exhaust riser and the aqua lift muffler. The hump hose is more flexible than standard exhaust hose. It will help prevent damage to the muffler caused by the harsh vibrations of the diesel engine. See "May we also suggest" below.
• Inlet: 1-1/4"NPT threads
• Outlet: 1-7/8" diameter
Refer to the annotated drawing at the left for more dimensions.
Not compatible with "B" series engines, which use 1-1/2" NPT threads and typically used a 1-5/8" diameter outlet.
1) CAUTION! This exhaust riser must be used with a properly installed thermal jacket. Due to the extreme fire hazard, we include the appropriate Thermal Jacket with each riser. Installing a riser without a thermal jacket is an extreme fire hazard that could cause death or serious injury and the complete loss of your boat.
2) We cannot overstate or take responsibility for the extreme danger inherent in an inboard engine's exhaust installation. We strongly recommend you have an experienced boat yard perform exhaust system repair or replacement.
3) Never run your engine without a properly installed Thermal Jacket. In every Catalina installation there are combustible materials close enough to the riser to start a fire.
4) This item does not conform to the shipping table in the Shopping Cart. Additional shipping must be calculated. When you place your order we always call with a shipping quote before billing your card. For a quote in advance, just call 800/959-7245.