You won't find it there, the 500 Electra uses the AVL "lean burn" engine with quite a few design changes. From the factory it would have had an exhaust valve lifter mechanism located in the finned tappet cover, it would have had a cable-operated lever pushing against a flanged collar on the exhaust tappet. The cable was supposed to be operated by a rather feeble plastic lever in the left-hand side handlebar switch cluster.
As supplied it never worked well, many owners junked the whole set-up and just fitted a plain tappet cover, others managed to get it to work better by using a vintage-style metal valve-lifter lever on the handlebars, which seemed better able to cope with the effort needed to fit the exhaust valve off its seat against the force of the valve spring.
A.
Well, again I'm a little late to the fair. Didn't read this until Sunday night at almost 9:30.
The decomp on the AVL doesn't work "exactly" as you described, A.
You aren't "lifting the exhaust valve against valve spring pressure" when you pull on that insufferable plastic lever. You can pull on it all you want and you're not going to lift that valve off its seat.
What happens is the engine has to be turning over as you pull on the lever. Pulling on the handlebar lever lifts the lever on the tappet cover which then rotates a cam that then jams against the collar on the pushrod and prevents the pushrod from coming back down AFTER it's been lifted by the rotation of the engine. It essentially holds the valve open AFTER it's been opened by the rotation of the engine.
The lever, in itself, is not lifting the pushrod.
Matters not, however, as Sigreen is installing the much more sensible system.
I did away with the whole mechanism on mine quite a while ago; lever, cable and tappet cover.