A 1993 Force-Fed Custom Kawasaki Vulcan 1500

"The ugliest motorcycle" makes its mark.

1993 Vulcan 1500
Cliff Randall gave his 1993 Vulcan 1500 a makeover and transformed it into a show-stopping custom.Fran Kuhn

Cliff Randall has ridden them all. After 24 years of riding and racing “outrageously modified sport bikes,” as well as building a custom V-Max, Randall received a ‘93 Vulcan 1500 from his wife, Maralyn, for his 40th birthday. Although he thought it was “the ugliest motorcycle” he had ever seen, one press of the starter button told him the bike had potential. The Randalls rode the Vulcan two-up for a year until Maralyn decided she wanted a cruiser of her own. Seeing an opportunity, Cliff bought her a ‘94 Shadow VLX, and once she settled in on her own ride, he quietly slipped the Vulcan into the garage and went to work.

While leaving the engine internals untouched (“You don’t have to rev this bike to make it work!”), Randall bumped the Vulcan’s output from 74 foot-pounds and 52 rear wheel horsepower to 86 foot-pounds and 63 horsepower simply by helping the engine breath freely. Of course, the process wasn’t simple at all.

“You don’t have to rev this bike to make it work!”
“You don’t have to rev this bike to make it work!”Fran Kuhn

Randall began by modifying the stock air intake system to build a ram air system out of the existing air box. He cut one inch off the snorkel behind the T junction of the intake plumbing coming from both of the unsightly air filters, which resulted in an open snorkel tube facing directly forward in clear air. Next, he wrapped the open snorkel with metal screen and foam filter material to keep the dirt out. At speed, pressurized air now forces its way directly into what is an otherwise stock air box. Maintaining the stock air box volume helped to keep the air’s intake velocity high at low to mid range rpm (around-town cruising speeds), giving smoother power prior to the onset of the ram air effect in the top end. To assure that the twin CV carbs function properly at the higher than atmospheric pressure created by the ram air system, Randall routed the float bowl air intake lines up to the front of the snorkel to balance the carb pressure.

While most of us would be happy with a Jardine exhaust system right out of the box, Randall had to put his touch on that too. First, all of the mounting brackets were strengthened to withstand the 1500’s increased power and vibration, which he claims destroyed some aftermarket systems. With the engine gulping down the fuel-air mixture in larger bites, Randall next addressed the escape route of all those hot expanding gasses. He felt the Jardine’s one-inch-diameter baffles were too restrictive, so he built his own two-inch units, giving the exhaust note what he calls “a sweet rumble.”

1993 Vulcan 1500
The lean, clean view from the saddle. Where’s the speedo? Who cares?Fran Kuhn

As others have discovered to their sorrow, simply bolting on a freer breathing pipe and modifying the intake tract of an engine doesn’t necessarily result in superior power delivery. Only jetting can utilize the higher potential afforded by less restrictive flow into and out of the engine. Randall spent many man-hours testing his Vulcan on both a Dynotronics dyno and the street (to make sure that the increased performance didn’t compromise streetability). The carburetors’ main jets grew from the stock 112 front and 115 rear to 138 for both carburetors. However, Randall didn’t stop there; his research showed that the thinner air during the summer heat required slightly leaner 136 main jets for optimum performance. He also shimmed the needle jets with five carburetor washers each, and backed the mixture screws out from the stock 13⁄4 turns to five full turns, remedying the lean backfiring that big twin riders find so annoying when decelerating with a closed throttle.

Randall’s engine now delivers 20 percent more power without any internal modifications or black-box highjinks. The dyno charts show not only the increased power from the baseline dyno run, but also smoother torque and horsepower curves with fewer peaks and valleys—all without the benefit of the ram effect from the bike muscling its way through the atmosphere. Randall’s seat-of-the-pants estimate is that, on the street, the ram air adds another 10 percent to the 1500’s prodigious power delivery although we would expect the actual boost to be a bit less.

1993 Vulcan 1500
Randall decided to lower his Vulcan three inches and also cut two inches from the sidestand to prevent the bike from tipping over when parked.Fran Kuhn

The Vulcan’s appearance was Randall’s next stop on the custom highway. He lowered the bike three inches by replacing the stock 13.5-inch shocks with 10.5-inch chrome Progressive Suspension dampers. The front was lowered a similar amount by sliding the fork stanchions three inches higher in the triple clamp. To facilitate this change, the upper triple clamp had to be drilled to accept Custom Chrome’s four-inch bar risers and drag bar. Although the ground clearance was reduced, the firmer ride provided by the Progressive shocks and thicker 20 weight fork oil keeps the hard parts off the ground. Since the frame was lowered, Randall also cut two inches from the center of the sidestand to keep the bike from standing too upright and risking a tumble when unattended.

The Plating House provided the chrome for the sidestand, fork sliders, triple clamp, shaft-drive hub, handlebar switch boxes, master cylinders, brake calipers, brake discs, coil cover, footpeg assemblies, modified exhaust system, rear brake stay, the engine cases, and water pump cover. Rocket Motorcycles powder-coated the wheels silver to complement the chrome and the paint. Braided steel brake lines add more stopping power and sparkle to the bike’s front end. The dummy air cleaner cover was “stolen late one night from a neighbor’s ‘95 Vulcan Classic” (Although we’re sure it was more like an extended loan.).

Next, Randall’s Vulcan underwent some serious dieting. Any brackets or parts he deemed unnecessary, immediately took up residence in the trash bin. When he was finished, the instrument cluster, speedo, rear pegs, horn mount, reflectors, and turn signals were all consigned to oblivion. Additionally, the radiator frame was removed from the core, shaved down for a sleekened look, and repainted. The front gas tank mounts were cut down by one inch to level the tank and give the lowered bike a longer, more streamlined appearance. The rear fender and swingarm were also reworked, not as part of a diet plan, but to handle full-suspension travel with a beefy Metzeler 170/90-15 rear tire. Topping the fender is a Corbin Gunfighter saddle that Randall had thinned and altered to fit the look of the lean Vulcan. After the dust settled, Randall’s Vulcan weighed in at 555 pounds wet—60 pounds lighter! One look at Randall’s Vulcan shows how successful he was in erasing the stock bike’s weak points while maintaining its lines. Randall didn’t want the new paint scheme to clutter up his Vulcan’s clean look with a lot of flashy graphics. Instead, he chose to have The Wizard maintain the original Kawasaki design with silver on a base of metallic black with red pinstriping. From a distance, the low-key color scheme looks subdued, but closer inspection rewards the viewer with a deep black metallic sheen, distinguishing the bike’s paint from a stocker.

A year after beginning his project, Randall was rewarded for his effort. His 1500 made history by finishing higher in the standings than any previous Japanese cruiser at the 1995 Canadian International Motorcycle Super Show, placing 7th in the Pro Builder’s Class, a class traditionally occupied and judged by Harley enthusiasts only. Randall says he wins out on the boulevard, too. His bike makes quick business of anyone foolish enough to challenge him to a top gear roll-on contest. From the looks of his dyno chart, he better be holding on when he pulls the trigger!

This article was originally published in the August 1997 issue of Motorcycle Cruiser.