salt water vs fresh water

ramblin · Post by **ramblin** » Sun Nov 20, 2011 10:38 am

I've been considering a 12 meter internation aft cabin as a potential part time live aboard and saw a decent one last year near Detroit. This week end i traveled to NJ and saw another but lots of issues. binnacles and most every metal part on bridge were very pitted, one throttle wouldn't even move. Ice maker on back deck rusted out, facet pitted. Detroits started but lots and lots of smoke. Broker said it was the nature of 2 cycle engines. also said turbos needed rebuilding.

I think i'm going to pass on the boat but was wondering how much of this is due to salt water/air vs just poore upkeep by owner? should i stick to looking at fresh water boats?

Also the amount of smoke on startup just about engulfed the marina, is there some thing wrong with the engines, do detroits do this all the time, would cats etc also do it?

prowlersfish · Post by **prowlersfish** » Sun Nov 20, 2011 6:32 pm

How cold was it ? where block heaters in use ? How soon did it clear up ? How many hours ? . How well did it start ? what Detroit ?

If it was very cold and the smoke cleared up fairly soon could be normal .If it was warn out and the smoke did not clear up much then it could be time for a overhaul ( pistons and liners ) run Farly hard you can plan on 1500-2000hours on a overhaul assuming its the 450 or 485 HP engine (if a 671 ) or 550 hp 692

Commissionpoint · Post by **Commissionpoint** » Sun Nov 20, 2011 6:39 pm

I would think DD 671T's in that boat. 92's perhaps. 2 stroke diesels definately like to smoke on a cold startup. As mentioned, if it cleared up fairly quickly it might not be a problem.

ramblin · Post by **ramblin** » Mon Nov 21, 2011 12:52 am

The engines were DD 671's with about 1200 hrs. it was about 50 degrees out and smoke did clear up within a minute or 2.

Would a 4 stroke like a cat also smoke like that on startup?

alexander38 · Post by **alexander38** » Mon Nov 21, 2011 4:50 am

did it ever clear up ?

Allen Sr · Post by **Allen Sr** » Mon Nov 21, 2011 5:18 am

ramblin wrote:The engines were DD 671's with about 1200 hrs. it was about 50 degrees out and smoke did clear up within a minute or 2.

Would a 4 stroke like a cat also smoke like that on startup?

Normally a 4 stroke won't smoke like that unless severely worn out. I have seen the 3208 cats smoke like a DD671 until they warm up when they have quite a few hours (miles) on them. My experience with the diesels is mainly in medium and heavy duty trucks though.

prowlersfish · Post by **prowlersfish** » Mon Nov 21, 2011 6:36 am

ramblin wrote:The engines were DD 671's with about 1200 hrs. it was about 50 degrees out and smoke did clear up within a minute or 2.

Would a 4 stroke like a cat also smoke like that on startup?

On a cold day they could . a aftercooled one more so . they don't have air heaters like some do . using block heaters will help a lot . I start using them when the temp drops

alexander38 · Post by **alexander38** » Mon Nov 21, 2011 6:29 pm

But how long did they run ? when warm did they still smoke ?

ramblin · Post by **ramblin** » Mon Nov 21, 2011 7:58 pm

after about 2 minutes they stopped smoking, but boy for those 1st few minutes the mairna was filled with smoke. i do have to guess that the engines hadn't been started in some time as the broker said the current owner never takes it out.

alexander38 · Post by **alexander38** » Tue Nov 22, 2011 6:13 am

then as some have said and from what goes on with all my oil burner trucks I'd go back and pre-heat the engines and see how they do, and if they smoke less and you want the boat have the engines inspected by a mechanic that YOU pick...and go from there....just my 2 cents....

Commissionpoint · Post by **Commissionpoint** » Tue Nov 22, 2011 8:23 am

alexander38 wrote:then as some have said and from what goes on with all my oil burner trucks I'd go back and pre-heat the engines and see how they do, and if they smoke less and you want the boat have the engines inspected by a mechanic that YOU pick...and go from there....just my 2 cents....

+1. Good advice. Warm them up and then see how they smoke.

I love DD671's if they are naturally aspirated. 3000 hours isn't uncommom between resleeving. On the other hand 1500 hours can be pushing it on a turbo equipped model, espescially if they aren't taken care of well.