Universal XP riser issue

[AXEL]

A heads up, check your riser. Started the boat up last weekend and with in seconds the riser blew off. A clamp that holds it on broke. Looking at this clamp, a "T" type SS clamp with a bolt that has a barrel on one end, the barrel broke clean off. It looks like it had been corroding for a while. Funny how I sailed/motored all last season and even winterized without any failure and it blows off in seconds during spring commissioning. That's the good news. It could have happened later in the season and stranded me. There is a gasket between the riser and elbow. The gasket was pretty much gone. Perhaps it slowly broke away causing the clamp to loosen and vibrate, causing the failure. Just speculation. In any case you guys may want to check yours out this spring. CO2 poisoning with a lose clamp/bad gasket, not good.

 

[Whatfiero1]

I always run a co detector battery operated. They say diesel doesn't make that much carbon monoxide but not gonna chance it incase kids want take a nap on long run

 

[LeslieTroyer]

For it to blow like that I would suspect a blockage in the exhaust. Maybe ice ??

 

[AXEL]

For it to blow like that I would suspect a blockage in the exhaust. Maybe ice ??

No clog. I took the whole thing off and gave it a good inspection. It was 100% SS clamp failure. But most likely caused by the deterioration of the gasket which allowed for slop and vibration between the riser and the elbow.

 

[Ward H]

Sorry, I’m having a hard time understanding what blew off. On my M-25XP the exhaust riser threads on to a flange that is bolted to the manifold. The other end has the hose to the aqua muffler. This is the only clamp on my exhaust riser. Is this hose what blew off?

 

[AXEL]

Sorry, I’m having a hard time understanding what blew off. On my M-25XP the exhaust riser threads on to a flange that is bolted to the manifold. The other end has the hose to the aqua muffler. This is the only clamp on my exhaust riser. Is this hose what blew off?

I should have been clearer, I have a M-25XP-B. The riser doesn't bolt onto the manifold, it clamps on. Two flanges, one on the riser and its mate on the manifold are held together with a SS clamp. I have owned the older model engines with the bolt on riser. I remember spending a week, every night with PB Blaster and a torch trying to get it off. The newer design eliminates that problem however as I have discovered, it's just one more thing to keep an eye on.

 

[Ward H]

Thanks Alex. I only know my diesel, which is new to me.
My riser flange won’t budge from the manifold but I can reach the inside around the water nipple and a little beyond and it feels clean I’m leaving it alone.

 

[LeslieTroyer]

Ward I think he is referring to these parts the male flange below screws into the manafold flange.