It is important to understand that there are no detailed records of how each of these early boats were assembled. The exhaust risers were assembled as needed as the boats were built. Please view the photos below under "More Images". Notice how the two old exhaust risers pictured have very different configurations. In addition, by the time it fails, it will likely be impossible to determine the angle of each bend that created your particular configuration.

To accommodate the variations inherent in a hand-built boat we have made our replacement risers adjustable. To fight the highly corrosive effects of hot diesel exhaust gases mixed with salt water we use type 316 stainless steel wherever possible. Even the welding rod is type 316. Then, to make it even more corrosion resistant, we have all of the parts electropolished to remove ferrous metal from all surfaces of the assembly including the inside of all tubing, fittings and welds.

The only way to remove the exhaust riser 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".

See the annotated image at the left for all of the pertinent dimensions.

1) CAUTION! This exhaust riser must be used with a properly installed thermal jacket. 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) Due to the extreme fire hazard, we include the appropriate Thermal Jacket.

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) 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.

5) 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.

6) This riser is equipped with 1-1/4"NPT size threads and is not compatible with "B" series engines, which use 1-1/2"NPT size threads.

7) The riser as pictured may not fit every Catalina 27 with the M-18 engine. Since the boats are hand-built, there can be subtle nuances that are different from one boat to the next. To ensure a proper fit, we require you send us your old riser.