I need a new engine!! ugh

[Mark Sutherland]

Great information Leigh, Russ and Bill. Without any guidance to the contrary, I think a 1,000 hour, or 8 to 10 year interval might be a good spec for this elbow replacement. The risk/reward ratio goes off the chart the instant this component enters it's failure window. This is going on my maintenance schedule. Thanks again for the feed back!

[william vanwagoner]

One more note on riser replacement. My engine was originally plumbed to the starboard inlet of the riser from which the hose went down and around before going up to the anti-siphon loop behind the steps. When I replaced the riser again this year I used the port side tap on the riser instead of the starboard tap leading to a much more direct route to the anti-siphon loop (note that there are two inlets on the riser, one on each side, and the inlet not used is fitted with a threaded brass plug). I also replaced all the hoses and used bronze fittings for the different size hose splices instead of the plastic fittings that originally came on the hoses with the anti-siphon kit.

[TBOT422]

HI All, OK so you have convinced me it is time to replace our exhaust riser. Is anyone certain of the part number. We have the M-35B. Our casting says Westerbeke 36734. When I Google that, it says it has been replaced with the 37403. It appears correct, although it is red. When I Google exhaust riser for the Universal M-35B, I get part number 200490 at Discount Marine Source, but it is silver not red.

I'm also not able to locate the Mainsheet article referred to in another thread. I don't seem to be able to fine the technical articles for members on the main page that I used to be able to see. Any ideas?

[leigh weiss]

I got the red one. A little spray paint and poof, it is silver/blue.
The part fit and works fine.
You still need to find the root cause of water intrusion.

[william vanwagoner]

I have done this twice now and both new risers were purchased under the new part number 37403, but had the old part number cast on the side. I think they changed the part number on paper but were to lazy to change the casting, and yes, they were painted fire engine red. My latest riser was purchased from Discountmarinesource.com in January 2019 (yes, it took me almost a year to get around to changing it), under part no 37403 at $234 for the part and $7.95 for shipping.

As for the article, in the members only section of this website there is a technical info section which is where all the Mainsheet articles are. If you are still not able to retrieve it send me a private message with your email address and I will forward the pdf to you (it is too large to attach within the messaging platform on this site)

[KenKrawford]

Gary, is this the article you need ?
https://catalina350.com/technical/artic ... 0riser.pdf

[TBOT422]

Yes Ken, that is the article. However, I think my issue is that when I go to the main C350IA page and select Members Area, it requires a password, and I have no idea what that password is anymore (recently upgraded computer). It is certainly not the password for my account on the forum page. Could you PM the main page password to me?

Thanks

[Mark Sutherland]

Hi Bill. Your Mainsheet article mentions 182 hours and 5 yr service interval. Based on your experience, at what interval would you recommend replacing the exhaust riser, and would you lean more towards a calendar-time interval, or engine hours? Thanks!

[wolfe10]

I suspect BOTH engine hours AND calendar time are part of the equation for exhaust riser replacement.

We use the boat a lot more than 182 hours/5 years (or even per year).

Unless it has been abused (overheated) my opinion would be 1000 hours/5 years.

Very easy DYI job.

Yes, if you are having overheating issues, a good time to both replace the riser and boil out the heat exhanger (I use muriatic acid) along with coolant change.

[Pgtjs]

Hi folks,

For what it is worth at this stage ( I have been out in the San Juan islands for a week or so and could not reply earlier), I have a Yanmar 3YM30 which was factory installed new when I ordered the boat in 2006. I had had a Universal Kobata diesel - I think the same as the Westerbeke model, in a previous boat and had no end of problems with it: principally breaking pencil zincs and glow plug and fuel pump mountings as I recall. Two boats later I was trading up from a C320/Yanmar due to a warranty issue and the factory were very helpful in meeting my condition for an order - I think they charged me an extra $500 at the time. I seem to recall my present Yanmar is a 30hp v. 35hp on the Westerbeke but I found a comparison graph of the HP/Torque for each at the time and it was not meaningfully different.

I have a KIWI prop which was adjusted a couple of times to the right pitch and I seem to be able to motor all day at about 6.2-6.4 kts at 2800 rpm when the bottom is clean. It uses about 1.1 gph of fuel at that RPM. Another reason for avoiding the Kobata engine ( actually a marinized 1940s Austin car engine from England originally) was that they were assembled/made then by Medallist Industries in Oshkosh WI. I lived close by and several of their engineers belonged to same Yacht Club so I heard war stories about the product. In fact, the Yacht club had many failed blocks which were bundled and used as anchors for mooring buoys for our member's boats. Incidentally there was also a Mercury Marine factory down the road and we had a collection of their expired blocks as well: "recycling at it's best".....

My Yanmar has now done 2200 hours and I have not replaced the Exhaust riser but based on this discussion I will do so. Actually another Yanmar 3GM30 owner had a pin hole leak in the riser some time ago and replaced it - he thinks it maybe had a couple of thousand hours on it at the time but cant remember. So this is obviously a critical maintenance item which is not clearly documented. I am also interested in the comment on the need to clean out the heat exchanger - I have had it flushed perhaps every 500 hours but what is suggested by those who might have had a clogged/overheating issue with the exchanger system? There was a thread on another Catalina owners website or perhaps an article in the magazine many years back which I cant find now. Any one else recall it?

I will appreciate any feedback on these topics.

Cheers folks, Geoff. S. C350 #392, Taeko 1V, Semiahmoo WA.

[william vanwagoner]

I tend to be very conservative when it comes to the exhaust riser given the damage to the engine that could result from failure. My first riser went about five years without much wear and with low hours. My second riser is about 9 years old and the engine now has roughly 380 hours, but I have not cut into it yet to determine condition. For me. I would replace it every 5 or 6 years for high use engines but go no longer than 8 to 9 years for low use engines.

Regardless of the number of hours of use, salt water sits inside the casting all the time and some corrosion will occur. I remember the first riser had quite a bit of corrosion in the area of the water inlet to the point flow would have been a bit restricted. Prior to when the photos were taken I scraped out quite a bit of the corrosion to determine how deep it went. The saving grace in the design is the thickness of the aluminum walls on the riser. It will be interesting to see what the inside of my latest riser looks like after about 200 house of use in about 9 years. Regardless, I think $250 or so and an hour of time every 5 to 9 years is cheap insurance when compared to a $20k plus engine replacement.

[D&M]

Like the Yanmar and Volvo versions. Is there a stainless steel replacement option?

[jrohrbaugh]

Here are the pictures that I don't think got attached.
Jamie
Sail #444
S/V Soixante

[ElizabethG]

Hi Jamie,

I replaced my riser this past week.

Your pictures closely depict the condition of my riser inside and out.

My boat is a 2004 with 1,600 hours and the riser had never been replaced (salt water environment).

I was expecting the interior to be pretty clogged up, but it wasn't...just some pitting.

I spoke to a guy on the dock that has a trawler with twin Cummins turbo diesels. He takes his risers off and has them "boiled out" and puts them back on. The risers for our 350's are cheap enough to just replace them.

The replacement was pretty easy, but you'll need a torque wrench to properly tighten the bracket that connects the riser to the manifold. A one page instruction sheet is included in the kit.

Bill
S/V Elizabeth G
Hull # 193

[jrohrbaugh]

Thanks Bill.
Riser is now installed.
Just guessed at torque on clamp
Could not find wrench smaller than 20 ft lbs.
Anyway, nothing is leaking.
1940 hrs on 13 year old boat. We do motor sail a bit.

[wolfe10]

Here are the pictures that I don't think got attached.
Jamie
Sail #444
S/V Soixante

Looking at those pictures (outside of exhaust elbow), I suspect you have a lot of corrosion in the engine room.

If you store where you have shore power, I STRONGLY recommend a 30 pint home dehumidifier set at 50%. Leave engine access hatches open for air circulation.

We put ours on a piece of plywood, cushioned with a towel so it doesn't scratch the galley counter. Condensate drains right into the sink and overboard.

[jrohrbaugh]

Not much humidity or corrosion in engine
area.
Inside engine?
I regularly change zinc.
Doing that today as reg. maint.
Now the @%&#$ engine won't start.
Charger also dead.
Another adventure begins

[Mark Sutherland]

I'm looking to buy the exhaust elbow, PN 200490, as referenced here. On the discountmarinesource.com site, I see in the photo what appears to be a single round gasket (looks like a large washer). Is that the only gasket I'll be needing? Thanks.

[william vanwagoner]

Hi Mark,

As I recall the riser came with the clamp, round gasket, and brass fittings which is all you need. Not a hard job.

[mhedmankw]

I've read a lot of the posts on this topic here and on other boards as well but never paid much attention until yesterday. I overheated and had trouble burping during a maintenance session. The boat, not myself. During inspection I found no problems and then this morning I saw a mention in a Universal technical book about the manifold and how you should probe and clean the "weep" hole for the overflow bottle. I had thought to check it out the day before but thought "why" that could never plug. Well, back that up, I'd never seen one plugged but they're usually 1/4 to 5/16 diameter. How could that plug up? The hole on the M35 is only maybe 1/16 and it didn't make sense to me to just probe it so I pulled the brass elbow and "Holy Cow" it was plugged solid from end to end with stuff and the hole it fits into was plugged with aluminum oxide. I thoroughly cleaned the elbow and chipped away at the hole with a screwdriver and then using drill bits by hand until it was clean. After I put it back together and checked the flow through the hose I topped off the manifold and the "burping" problem was solved. The overflow tank is the primary method for the engine to purge air from the system and I've never seen this deficiency mentioned. I've also never seen such a small hole for that on any engine. Obviously they are trying to meter water flow so I'm not drilling it out but I will begin to monitor this. By far the easiest fix to this issue I've seen and my engine never budged off 160 at any rpm.