Colored hoses, Are they still available? Or has anyone tried dying a hose? Options

[TonyA]

Maybe i ma crazy but are these available anywhere, or has anyone ever attempted to bleach and dye a hose?

[JeffBowlsby]

w-pop, StarBear, I think you have made some interesting observations and I admire your research and efforts. After reviewing the posts, the 73 and 74 emissions manual diagrams, some photos I took of the plastic style charcoal canister in pieces, and my factory 914 parts book, I think there is a likely discrepancy, in the 1974 914 literature. Follow me:

Can we all agree that the functional purpose of the canister is to filter unburnt fuel vapor thru the charcoal matrix which then is transported to the intake for final burning rather than releasing the vapor to the atmosphere? If so we understand and agree on the operating principle. If so, then an air stream needs to transport that vapor through the matrix and then direct it to the engine intake air.

The 73 diagram shows the parallel flow of air supply stream from the engine fan and vapor stream, but the diagram also depicts a long tube from the vapor supply line which deeply penetrates the matrix, and if this were so, the vapor would mostly bypass the matrix just before it exits the canister. I think that is an issue.

The 74 diagram has the same charcoal canister diagram with the long tube but reverses the airflow. This seems logical. The vapor exits the long tube where it is deposited into the canister at the far end from where it enters the canister, then filters through the matrix carried by the airflow and exits through the canister end near where it entered. This seems plausible.

Thinking there may have been separate 73 and 74+ canisters I checked my factory parts manual and there were only two canister PNs listed, the early metal sealed tyle and the later plastic serviceable type. Two and only two part numbers over the 914 production.

I located the photos I took of an opened plastic canister. Note that there is no long vapor supply tube - vapors enter the canister near the end wall at a short stubby tube, not deep into the matrix. I don't recall and cannot tell from the photo what that smaller square white material is in the photos at that end, perhaps a filter fabric? If so it would retain charcoal dust from entering the engine if that end is also the airflow exit. At the opposite end a spring loaded air permeable plate compresses the charcoal and there is a filter fabric layer at that end. Functionally then, either end could be the airflow supply or exit end.

But...

If this end with both the vapor supply nipple and larger nipple is both the entrance and exit for airflow guided fuel vapors, because there is not the long fuel vapor tube as depicted in the diagrams, the the fuel vapor would not have have much exposure to the charcoal matric and hence only limited filtering effect. A short circuit as far as effective filtering goes.

So, given the actual construction of the 914 plastic charcoal canister, I am inclined to continue to believe at this point, barring new evidence, that fuel vapor and air supply enter at the same end, and exit through the single port at the opposite end to the intake...like the 73 diagram and my diagram both indicate.

What say you...