Page 15 - June 2020 Newsletter

June Return to
2020 `Triumphs Live On’ Start
Page 14
www.tswf
l.org
Tech Corner-continued

In all instances, the key component is the use of a charcoal canister to trap gas fumes from the gas tank and the carburetor
float bowls. The trapped fumes are then sucked through the valve cover, through the crankcase and out the vent on the
tappet cover on the side of the engine by carb vacuum. This system uses absolutely no energy to operate so it should be
left functional when you remove the air pump and other emission equipment. Over time, the filters and charcoal degrade
to the point of being sucked into the crankcase. One thing you do not want in your crankcase is bits of charcoal.

No servicing is required for the activated charcoal canister but the complete canister should be changed every 48,000
miles; repairing the charcoal canister is not all that hard. The first thing you have to do is to open it up and clean out all
the old contents. The bottom unscrews to expose the retainer. The retainer is the piece that looks like a ring divided into
thirds.

Disassembly of charcoal canister

Notice the ring has six tabs in it that fit in matching slots in the bottom of the canister. These have to be carefully depressed
so the retainer will be released. After the retainer is removed, you will find a filter made of plastic gauze. Pull this out and
examine it. If it is in decent condition set it aside for reuse. Under it you will find the old charcoal. It looks like black
pellets. Dump these in the trash. They are not re-useable. Under the charcoal you will find another filter like the first one
and a steel mesh screen. If the screen is intact, save it for reuse or replace it. Next you will find a special washer and a
spring. These should be cleaned up for reuse also. Okay, now you have it all out and in front of you. If the two filters are
not re-useable, you can make replacements from filter paper. I had access to some filter paper so I cut several 3-1/2"
circles. Lacking this, you can use plain old coffee filters. Look around for some large enough to cut the discs from without
leaving any holes. After you make your new filters, you are ready to go back together with everything.

Replacement charcoal for the Evaporative Emission Control System