Them Black Bits in The Carbs

[mcgovern61]

As we are cleaning out the carbs from the '81 Standard, I became a bit confused about something. Granted, these carbs sat with gas in them for nearly 3 years and the green slime is a mess. But, my question is the little bits of black rubber I keep finding though out the carbs.

The funny thing is, there are no black bits in the filter or any rust particles in the filter which also sat for 3 years. The filter is just slimy and discolored. Most of the rubber seals are in non-usable shape because they are flattened or dried out.

I know the ethanol gas does a lot of damage to the rubber if it is not Viton, but how come no rubber in the filter? It is a fine filter. There is a hose and petcock seal before the filter. Shouldn't that have shown up in the filter? Granted, the hoses are shot.

But the main location of the rubber bits and dissolved rubber was in the jammed float needle and the primary and idle jet air tubes.

If I am following the circuits correctly, the float needle is the entry point for gas to reach the bowl. So the bits of rubber have to come into the system before the bowls, but seem to not be caught at the filter.

My only guess is, maybe the fuel pump diaphragm is taking a beating from the ethanol and might also be breaking down? Are we possibly setting ourselves up for failure if that is the case with these old fuel pumps? :read: :headscratch:

 

[AApple]

There is the hose AFTER the filter, and another hose from the pump to the carby. Either can be deteriorated on the inside, and shedding crap into the system.

 

[ekvh]

I've had that happen. Slice them open and see if the pieces fit the puzzle

 

[kerryb]

I agree that a hose or seal breaking down is the most likely culprit, but don't rule out the possibility that these bits have another origin such as the chemical compounds in the fuel additives that have had time to accumulate and/or harden into bits from a liquid source. Just more colors of crap to be cleaned out.

pardon my run-on sentences!!

 

[zman]

Be sure and check the tiny screens under the float needle seat (if they are even still in there), Gently prod them with a blunt pointed object to see if they are torn, I would replace them if possible, they act to keep the tiny accelerator jet (in the carb throats) from getting clogged.
If the accelerator jets are clogged be sure and clear them, I used very tiny stiff wire and allot of patience but having them working made a difference from a stop or sudden accelerating.
To check them I put distilled water down the passage then blew air to check for a fine even spray.

 

[mcgovern61]

Thanks Jeff! I was able to get them out easy enough and sent them through the ultrasonic cleaner. They were not bad at all when they came out of the carbs, yet the float needles and accelerator jet and air tubes were covered in gunk.

 

[Ansimp]

Nice job by the ultrasonic cleaner Gerry. :good:
I am jealous... :yes: