Electropolished type 316 stainless steel exhaust riser assembly with a 1-5/8" long inlet nipple. We believe this riser was used on the Catalina 30 equipped with an M-25XP between 1986 and 1990. It was also used in the Catalina 34 and Catalina 36 when equipped with an M-25XP, or M-35. Includes high temperature anti seize thread compound for assembly.
Please see the additional images below for dimensional references. If none of the various risers we offer match your dimensions, you will need to send us your old riser to match.
Unlike the original equipment part, we have the 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.
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.
This riser is equipped with 1-1/4"NPT threads. It is not compatible with "B" series engines, which use 1-1/2"NPT threads.
Refer to the annotated photo at the left for more measurements.
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.
5) This riser may not fit every boat mentioned above. Since the boats are hand-built, we can never be positive that your boat is equipped as we expect. Only by matching the dimensions of the part in your boat to the dimensions in the photo shown below under "More Images" will you know if this is the correct part.