Help needed on MAN engine problem

[Roddy Hays]

Had a cry for help today from a friend far away on a desert island. He has a boat with a pair of R6 800's and contacted Europe yesterday with a plea for info.

He's just put the boat back in the water, and the first weeks fishing has been good, but he has noticed a fair amount of white/light grey smoke from the exhausts at idle. Far more than normal.

Daytime and water temperatures are normal. Same fuel as normal. Engines serviced regularly by a MAN mechanic (who flies out). Exhaust smells faintly of coolant, but all gauges normal. No other undue effects.

I suspect contaminated fuel - as it has happened to both engines seemingly at the same time. Head gaskets and piston sleeves are possibilities as well, I guess, but I'm not a mechanic like some of you guys are - so suggestions please, ladies and gentlemen !

The Racor system on the boat does not have a water trap, by the way. Which seems strange to me. And it's just a single paper Racor each side.

[whitey]

If the problem with both engines started together after fueling up I would say the problem is in the fuel. We have the 8cyl 800hp MANS in our boat and if we get a load of fuel that has a high sulfer content they smoke like crazy on start up and at idle.

[Deep C]

Both engines? Hmmmmm... If it was one I would think head gasket letting coolant through to the hot side. Two though? Sounds like you might be right with contaminated or wet fuel.

One thing he can do to possibly determine if its a head gasket is to either use his finger or a paper towel and dip it in his coolant. If he has oil or carbon in there then quite possibly that would be the issue...

Wish I could be of more help...

[Mud Hole]

Both Engines...Fuel

[BahamaLure]

Far flung desert island + single racors with no water trap = trouble

the Bahamas are not that far flung but EVERYONE there had serious fuel filters 'cuz even if you buy from the same place all the time you just never know what you gonna get! I have seen boats with double inline racors one coarse mesh, one fine as a precaution.

boat manufacturers in recent years (talking outboards here) have taken to not providing a spot to mount a racor saying that the filter on the side of the engine is sufficient - well HA! not likely for cruising the islands, mon!

is your friend still using the same load of fuel? try topping off from elsewhere and clean/change the filters and see if there is any improvement. There are also fuel conditioners available to treat contaminated fuel.

[Captain Fred Archer]

Rodsky,

Uh, oh! Sounds like water in the fuel to me too. I have had way too much experience with that sort of thing, including a runaway and a blown engine with low hours on it because it happened in the middle of nowhere and nothing could be done about it until landfall again and a good dose of fuel polishing, new racors, etc. Runaways and blown mills are very bad news and a simple sounding thing like water in the fuel at the wrong time and in the wrong place can add up to them.

If it were me, I'd quit running the boat immediately and empty the tanks and get the fuel polished. Hopefully there's a polisher available wherever your friend is. Then I would do whatever it takes to get a good set of Racors installed, with water traps, and I'd inspect them every single day. We HAD to do that down in Cabo, or risk the consequences of that grey smoke , leading eventually to all hell breaking loose and the outright danger of a runaway ! or a blown mill. Ouch!

I hope your pal gets it all straightened out.

[rugman]

if its burnin coolant the level should be droping

[Banshee]

I happen to have a set of Racor 1000's just sitting in my shop, I would love to get rid of. PM me the price is right.
JW

[tmas]

wierd you are not seeing any water in the racors. have you cleaned the air fitlers lately. with the mann 10cy 800hp on the boat im am running i am constantly cleaning the air filters. i just use the KN filter cleaning kit. but if there is no access to KN kit use brake cleaner and soapy water and let them air dry.

I would also change out you secondary filters. If your engines are the same as mine they mann mechanic told me to use the black ones they are the better ones to use. but needless to say change all filters and see what happens. best of luck i have had some great fixes on some remote islands before.

I also highley recomend a fuel attive for the tropics and i greatly helps with smoking issues expecially with my mans with ove 6000 hr on them TECHNOL 403 expensive but specially desiegned for the tropics.

[Roddy Hays]

Thanx for all the info Guys. It's all gone on the ether to the fella involved. I hope he'll solve the problem. Having spent most of my career on far-flung islands I know how it can be and how things can pan out. I'm sure it'll all end well.

tms : I understand that the boat (a Cabo) and the engines have a strange racor set-up, with a single old-fashioned non-glass window filter unit (the type we used to see back in the '70's). He says there is now way to see if there is water in there. I'm sure there must be a drain though.....

I'll let you know what happens - thank you for your help.