Stainless risers

I need new risers on my 7.4L Mercruisers and I found used stainless steel mercruiser risers for sale for cheaper than the new Barr cast risers. I would imagine this would be the best way to go since the rest of the engines are FWC and with stainless risers, in theory I would never have to touch the exhaust again. I have heard Mercruiser stopped making the stainless risers (pn 816900-C) because they wouldn't be constantly selling them every 5 years or so. Is there any reason not to go with the stainless and to keep replacing them with the cast ones? Thanks

SS ones work just fine if you can get them ,they never rust thru and dump water in the exaust manifold

Merc made a couple of different angles on elbows. Those look to be the 7* ones

I think Mercruiser stopped using the SS risers as another of their "value engineering" moves since the stainless risers are expensive.

On replacing Mercruiser parts with Barr castings, I have some experience with that and don't recommend them for one reason. I replaced 2 sets of risers and manifolds on a 390EC I owned some years ago with Barr castings. Because I wasn't familiar with the name, I decided to pull them off and check them after about 9 months. All 4 risers were severely corroded and 2 had seawater in them. I was probably days from losing 2 perfectly good engines because of it. I understand that there can be quality issues and was reasonably tolerant. However, Barr wouldn't accept the word or photographic evidence from my marina who sold them to us; they refused to replace the parts or refund the cost until we shipped the defective parts back to them to have their QC people examne them. They would not promise a date for a resoslution.

It eventually took 12 weeks from Mid-June to September to get an answer from Barr. They prorated the warranty, so I only got a portion of the cost back. Had I waited on Barr, we could easily have lost the entire summer on the water, but I didn't. I immediately ordered new OEM risers and manifolds from Mercruiser and installed them and only lost 3 days.

My advice is to get the stainless risers if you can and if they fit your application. If you cannot, then use OEM Mercruiser exhaust parts.

Thanks for all the advice. I ordered the SS risers so hopefully now I wont have to worry about them rotting thru and taking out an engine. Not to mention the cost savings of not having to replace them every few years.

I just got this boat and noticed an external leak while it was running so I pulled off the riser expecting to find a bad gasket or something and there was a hole right thru the side of it! How the engine is ok I dont know but im glad I caught it. The ones I am replacing are Osco and are definitely more than 5 years old.

I got the stainless risers but now I have a couple other issues. The factory oil filter bracket mounted to the top of the cast risers with the long bolts but the stainless ones don't use the long bolts, they bolt low by the base. Is there an adapter I can use or just get long spacers and reuse the long bolts from the cast risers? 2nd, The starboard risers have studs to mount the engine harness connector bracket but the port risers don't have any studs to mount the ignition module bracket so now I need to find a place to mount that. Lastly the raw water hoses going to the risers came in on a 45 but they need to be 90 degrees with the stainless ones so now I need a few new hoses. Is anyone familiar with any of these issues? Thanks

Snapon24 said:

I got the stainless risers but now I have a couple other issues. The factory oil filter bracket mounted to the top of the cast risers with the long bolts but the stainless ones don't use the long bolts, they bolt low by the base. Is there an adapter I can use or just get long spacers and reuse the long bolts from the cast risers? 2nd, The starboard risers have studs to mount the engine harness connector bracket but the port risers don't have any studs to mount the ignition module bracket so now I need to find a place to mount that. Lastly the raw water hoses going to the risers came in on a 45 but they need to be 90 degrees with the stainless ones so now I need a few new hoses. Is anyone familiar with any of these issues? Thanks

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The SS risers use a different bracket for the oil filter, and different bolts. Go online and find the parts breakdown to get the part numbers. Parts are available.

https://www.perfprotech.com/blog/articles/mercruiser-stainless-riser

If you have a remote located oil filter – When replacing the stainless riser exhaust system today with the cast iron riser system, it should be noted that you will need to order the remote oil bracket for the cast iron risers as well as the longer riser bolts to mount the bracket.