It never rains...(I need help from the panel please)

[Dave_Snelson]

...but it pours.

Brilliant weather in N Wales this weekend to launch CI. That was the good bit. Launched - started - filled up on fuel pontoon - all seemed OK. Got out of Pwllheli harbour and opened her up near the fairway. After two miles or so...hmmm...funny smell. Hot smell. Looked behind me to see steam coming out of the engine bay!! [censored]!!!. Slow down and stop s/board engine and open hatch to find it's burst a hose and although the block is fine, the exhaust manifold and riser are definitely hot. Y'know, the "hot paint" smell...and the bilge pump is hard at work.

Limp back on one engine and get engineer to fit new hose. Start the engine and rev it up...seems OK...then bang!!! The new hose gives out with an almighty blast, and I'm not kidding, it was like a fire hose!

To cut a long story short, we hauled CI out again and removed the risers on the s/boad engine to find them blocked with all sorts of crap.

These engines are 6 years old and the engine itself is fine. Its just the ancilliary marinising equipment fitted by Vile-vo that is utter rubbish. Cast iron with no coating! Utter rubbish - and it goes against all the basic engineering principls. HANG YOUR HEAD IN SHAME, VOLVO!

Anyway now got all the manifolds and risers off both engines and I have (thankfully) managed to recover all 4 manifolds - but all 4 risers are doomed. I used a screwdriver, coat hanger wire and a Karcher to achieve this.

Does anyone know a successful way to recover very badly blocked risers?? Or do I just buy new ones and be done with it?

Yours truly,

A very sad and dispondant Dave /forums/images/graemlins/frown.gif

 

[BarryH]

Depends on whats blocking them. In the past I've had good results with caustic soda. Even Mr Muscle oven cleaner has given good results. Soaking in diesel gets lots of crud out with a good poking afterwards.

 

[studgies]

central heating cleaner works!

 

[gonfishing]

Sorry to hear of your misfortune Dave, A real bastard especially on the first spin of the season. Being the "Jobs" comforter that I am, it sounds like new risers are on the order book!! Unless of course they could be re engineered??
You don't normally pull your boat out for the winter , is it possible that may have contributed to the accelerated corrosion? Lack of use over the winter??

Good l;uck and keep us posted.

Julian

 

[Solitaire]

Dave, this happened to me! Don't piss about, buy new risers. I had RK stick mine an acid bath and all sorts of things - nothing worked but eventually it burnt thru the riser gaiters and flooded the engine bay. It's false economy to try and fix the old risers - just bite the bullet and replace both sides at same time. O got mine from Keyparts.

 

[Dave_Snelson]

Hi Julian - the boat was out for the winter - and yes, I think new risers are on the cards

 

[Dave_Snelson]

Hi David - yeah I think you are right. I was just asking in case anyone knew of a miracle cure. The damn things are blocked solid, As I said, I have recovered the fannimolds OK, and in fact, they were only starting to block up as a result of restricted (for restricted, read non-existant) flow through the risers.

 

[Solitaire]

Just do it mate - I've been there, seen it, lost me bloody T shirt! You'll not recover them.

 

[ChrisChevey]

I have used cement acid ( USED TO CLEAN MIXERS AND STAINS, it worked very well

 

[BrendanS]

What's in cement acid that's not in normal acid ? Nowt. Cement acid is usually just a dilute hydrochloric acid.

Acid will make concrete/cement porous and hence less mechanically sound, hence the use of acid to remove coatings in mixers. At the end of the day, it's just a dilute acid mix.

As Solitaire has already stated, acid bath for risers is likely to cause as many problems as it cures, and concrete acid is not as 'strong' as a commercial acid bath. It will really depend on how badly the risers are affected by scaling, or other calcium deposits.

 

[NorthernWave]

I've used On-Off before which is a hull cleaner, Don't get it on your hands though!!!

Chris

 

[BrendanS]

Pretty mild for this application though. It won't harm your hands as much as concentrated acid

 

[andrewa]

Dave

Sorry to hear of your problems however if you are changing the risers surely best to change the manifolds as well. 6 years in salt water is excellent life it was recommended to me that they should be changed every 3 years regardless on raw water cooled mercruisers. Only downside is the price in the UK if in no hurry try these guys in the US I think they ship international though don't know how much for quite weighty items.

http//www.perprotech.com

 

[Dave_Snelson]

Thanks Andrew - to be honest, I didn't know what to expect in terms of life cycle. My engineering head would have me believe that Volvo could have (and should have) enamelled the water passages in things like this - its just standard practice elsewhere in industry where severe corrosion is a problem. But no! The manifolds have definately cleaned up well and the water passages are fine and descaled.

Thanks for the tip, but I am actually now in a hurry and I need the risers, so I'll try keypart.

 

[oldgit]

Re: Been there done that.

Had exactly the same problem on a pair of mercruisers complete with bursting hoses,nearly had same grief with Volvo 175 in my P25.It was only my experience with the Mercs that made me remove the riser on the volvo to find it full of crud and scale.Two days poking,drilling and chipping did clear the channels.Lord knows how any water was getting through but the engine show no sign of overheating.Guess it was waiting for those finally few flakes to close of the channels competely.Have a look at www.yachtsurvey.com for a rundown on the evils of cast iron risers.It is one of the problems with raw water cooling systems,and as the site mentioned above ses nobody nowhere at this end of the market is going to stump up a shed load of dosh for stainless risers.

 

[[2068]]

Both Vilevo or MurkRuser have used internally coated manifolds/risers for a while, but the hot exhaust gasses, the salt, and the "scale" and gunge all take their toll. Normal life is 3-5 years, so you did well.

You could have specified a "closed" cooling system, but it's a bit late now...

dv.

 

[ShipsWoofy]

Have to say, while standing on the fuel pontoon with Dave watching the second pipe burst he remained calm and collected. Any normal man would have jumped up and down screaming at his Gods. But Dave just brushed off the disappointment with a smile and organised pulling Coney Island back out on to the trailer.

Must also congratulate his decision to return to Pwllheli, rather than carry on on the single engine. It was a flat calm, prefect crossing conditions, yet he erred on the side of caution and returned. Hindsight showed his port engine might also have failed on the way over. Many people would have plodded on, hoping to repair once they were back on their home mooring.

I have to say, I have never seen a hose burst like this, hoses popping off is one thing but bursting! The engine started, sounded lovely, then pop, water pouring out of a thick walled hose. The pressure must be immense, remember I am a raggie and have an awe inspiring 9hp available to me from each engine.

So I think the forum should be very nice to Dave for a full week, poor guy, no one has told him yet that his swim platform has been stolen while his boat has been in the yard this week. You can't trust anyone!

 

[BrendanS]

He's a powerboater! of course he'll take things like this in his stride, it's normal!

 

[ShipsWoofy]

You just used the words powerboater and normal in the same sentence. tee hee.

that's just silly /forums/images/graemlins/grin.gif

 

[Dave_Snelson]

D'ya know - I've got some stainless tubes and fittings that I bought for a job. Funny that - they are now a different shape...a sort of new swim platform shape. /forums/images/graemlins/grin.gif

BTW - to return the compliment, I think you remained quite composed whilst stood too close to a bursting hose /forums/images/graemlins/laugh.gif

Proposed re-launch...Sat 5th. /forums/images/graemlins/smile.gif