Issue link: https://read.dmtmag.com/i/787665
74 nMarch 2017n www.thunderpress.net THUNDER PRESS 11. …and is designed to take up the slack in the factory arrangement… like this! A simple, brilliant solution to an annoyance resulting from the realities of mass production. A way to sort of "blueprint" your rocker shaft mounting, for lack of a better way to say it. Less wear, less noise, all good! 12. Next up, and perhaps the best upgrade of the bunch, is the installation of the newest factory breather design. A vast improvement over ineffective "umbrella" valves! This black one is for the front cylinder. The rear breather is a sort of tan/ beige color… coded so as not to mix them up… they only really fi t one way. And they do not fi t earlier lower boxes (see #6)! Don't forget the red seal! 13. Now, before any reassembly comes the only mod required. The center "D-ring" must have the area that held the original umbrella valve cut out! Use a hacksaw, power saw, grinder, a fi le, any or all of the above… your choice. What you don't have a choice about is retaining the inside "lip" in this area of the box. That lip holds the box sealing rubber in place so don't let it disappear! (Or, try to fi nd a couple of good center D-Rings from an '86–'90 four-speed Evo XL… they don't have 'em, so you won't need to cut 'em.) 14. Snip the section of the rubber D-ring gasket to match the cut in the D-ring, and your mods are complete. Assemble the lower box completely and… 15. …place the Cometic (or equivalent) gasket on the head. Then install the lower rocker box. Yeah… this can be fi ddly since you don't want to "stick" this type gasket in place with any- thing. Do it dry and take your time. (An extra set of hands can be a good thing for this task.) 16. Oops! Probably should have mentioned this earlier! Just in case you haven't already, now is the time to inspect the tips of the pushrods and both of the working ends of the rocker arms. Nothing to report on a 700-mile Sporty, but any bike with tons of miles on it deserves a close look at all contact points, and replacement if wear is as bad as the dorked-up tip shown here. Motorhead Continued from page 69 See "Motorhead," page 77, column 1