3.0 carb question

[LilRedNeckGirl]

basics, 1985 3.0 in a wellcraft 248 sportsman, running twin setup.
a few years back, we bought this boat and did nearly a complete redo. now going on two years no major issues. spring pre season maintanace has us under the engine hatch pokin around and i noticed something.

the issue.
the carbs both have the clear ? vapor tube ? that runs from the carb, down to a fitting on the fuel pump.
this tube has begun to get a 'green' buildup in it. one engine has this buildup at the fuel pump end of the tube, the other has it up near the carb.
what is the green stuff?
is it normal or is there an underlying issue?
does this fall into the ' just replace the tube every year' catagory?

now, additional info, when we bought the boat, these tubes were clogged nearly solid with this greenish gunk. { it appeared at that time, to be an oily gunk, with a consistancy of light grease.} We had both carbs rebuilt by our mechanic, we installed two new fuel pumps, { the old pumps worked, but had set for 8 years }, and we replaced the clear tubes with new.
The carbs / engines have been flawless in preformance and dependability, start every time, never miss a beat. We run water seperators on each seperate fuel line, have a clear inline filter after the pump / before the carb, @ a window into the fuel system. the recent seasonal change showed only normal & reasonable contamination in the filters.
Fuel is always a premium blend of mid grade without ethanol.
Winter storage is always with a fuel storage addative, and a sea foam addative is run as maintanace a few times during the season.
oil is changed 2 times a year and always kept up to level and clean.
typical engine run time is at a comfortable 3000 RPM cruise, running about 45 minutes. very little idle time is typical.
engines are always brought up to about 160 degrees, normal operating temp, before we start out each morning.
Sooo, any ideas on the green stuff, causes, need to worry, or something that needs fixin?

 

[Cheetah 210es]

Re: 3.0 carb question

I've seen it but no idea what causes it, maybe a reaction to the material? As long as the pipes are not brittle and secure I wouldn't worry about them

 

[timfives]

Re: 3.0 carb question

You don't happen to have any pictures do you? the only two things i could imagine creating a greenish color in that, would either be antifreeze or Algae. Perhaps there was a little condensation in the tube and gunk just started to grow?

I've also heard those tubes turning green from coolant, but can't imagine that is your problem as you'd have other issues..

Just my thoughts..

T

 

[LilRedNeckGirl]

Re: 3.0 carb question

i dont think its a reaction to fuel vapor. we have used the same type tube on weed whackers etc, and fuel typicaly turns it an amber color after a few years. this is green, and it builds up like a grease/ gunk in the line. its taken a season and a half to build up to the point that color is now evadent, so no clogged lines yet, but never less, its starting to show.
at least your seeing it also, which means its not isolated to just my boat & there should be a solid answer for it.
just foot noteing here, the green is about the same color as brass corrosion, that light greenish tint.

 

[LilRedNeckGirl]

Re: 3.0 carb question

i just cant see coolant getting in there, its a tube from carb to fuel pump, no coolant in that system..
algea, hmmmmm im going to pull the tube, swab it and bleach it, if its oil/grease, color wont change.

 

[timfives]

Re: 3.0 carb question

Yeah, i'm note sure how you'd ever get coolant in it either, but stranger things have happened.. and its generally green

 

[Cheetah 210es]

Re: 3.0 carb question

The pipes are a safety feature in case the diaphram in the fuel pump splits so there shouldn't be hardly if any fuel in there if diagphram is good. When I fitted my last fuel pump it was greased from manufacturer with a blue/green grease so I put it down to that.

 

[LilRedNeckGirl]

Re: 3.0 carb question

I know its a vapor/safety tube, and ours were not supplied with the new fuel pump, installed, sans greese, they were totaly clean & clear. The carbs were a fresh rebuild at that time, again, no grease added. Also, the green is not fuel, none of the additives we use are green, Stabil = Red, Sea foam = nearly clear.. so im not thinking the diaphram is leaking.
I gotta get to work, but by this evening, ill have done the bleach test to see if, as noted eariler, it is condensation & algea growth.... We have some tank test paste, the kind that turns pink with water contact, Ill dab that also to see if it contains water.

 

[series60]

Re: 3.0 carb question

I know its a vapor/safety tube, and ours were not supplied with the new fuel pump, installed, sans greese, they were totaly clean & clear. The carbs were a fresh rebuild at that time, again, no grease added. Also, the green is not fuel, none of the additives we use are green, Stabil = Red, Sea foam = nearly clear.. so im not thinking the diaphram is leaking.
I gotta get to work, but by this evening, ill have done the bleach test to see if, as noted eariler, it is condensation & algea growth.... We have some tank test paste, the kind that turns pink with water contact, Ill dab that also to see if it contains water.

I would suggest going to your nearest small engine repair/lawnmower shop and buy the clear fuel line and replace both lines from the fuel pumps to the carbs. Run the engines and monitor the lines to see if fuel is coming up from fuel pump. If there is fuel in these lines then the diaphragm in the fuel pump is failing.

 

[LilRedNeckGirl]

Re: 3.0 carb question

We do moniter them, no fuel in the lines. The green stuff is not algea. I swabed it out, and it is unaffected by bleach. stays green after soakin in bleach for 4 hours....
I checked to see if it could be brass related corosian, , doesnt seem to be the isue, brass fitting its connected to was not corroded.
For sure ill be replacing these lines as they are two years old and only a buck or two for replacments. Just concerning as to what is causing the green stuff. A problem solved over the winter storage is much better then one discovered, on the water, 20 miles down river from home port....

 

[Pete104]

Re: 3.0 carb question

I know exactly what your refering too.
It has to be form of electrolosis. The brass being sacrificial. Brass into cast alumininum.
Keep the tubes fresh every couple years & keep the hole in the fitting open without removing it. If you ever cross thread that fitting, you'll hate yourself. Just push the crud thru it. It falls into a chamber that will never get to engine in the event a ruptured diaphram.
Don't forget to keep the fitting @ the pump clean. It gets all gunked up with dried up oil.

 

[LilRedNeckGirl]

Re: 3.0 carb question

Well, Im going to go on that assumption. A form of electrolisis, combined with normal carb gases and vapors. Im guessing the fist set of hoses, on the boat when we bought it, were probably origional from 1985. We bought it 3 years ago, and have run it around 2 years now. Its jut now that we are starting to get a color in the tubes, compared to clogged tubes on the origional tubes.
So , We shall replace the tubes, and then just add that on the things to watch list.
Appriciate everyone that had a thought on this, as apparently, its a common issue, with no real solid explanation..

 

[90stingray]

Re: 3.0 carb question

I always thought it was a reaction from the brass fittings. Brass usually corrodes a greenish color. Like I said, just my thoughts.