This 1993 Suzuki GS500 was my first street bike and I started working on it the day after I brought it home. The first mod was a simple swap to a flat handlebar with bar end mirrors. I then learned the hard way that Suzuki applied their tank graphics underneath the clear coat when I tried to remove the pink squiggle graphic from the red tank. I’d love to have a chat with the guy that though that was a great color combination. The botched decal removal led to a series of custom rattle can paint jobs. Truth be told, the GS500 was one of my earliest projects and I learned on that bike. Mistakes are a part of that learning process, and the little Suzuki took its lumps.
If your project is incomplete without Motorcycle Ignition Coils, look no further. We have quality products for your Suzuki GS500 from brands you trust at prices that will fit your budget. In search of more power I drilled the ignition rotor five degrees advanced, a home machinist trick for some free horsepower learned on the GSTwin forum, instead of buying an expensive aftermarket ignition advance. The Suzuki’s Mikuni carbs were jetted and capped with pod filters, and a full Vance & Hines Supersport exhaust system helped the.
Over time as my confidence and mechanical aptitude grew, the modifications became more ambitious. I replaced the rear shock with an adjustable GSX-R unit, and then swapped a late model GSX-R front end on for beefier, adjustable forks with big dual caliper brakes and billet triple clamps. There’s not much in the way of performance rubber available for the Suzuki GS500’s puny stock rear wheel, so I tossed it in favor of a wider wheel from a Bandit. The Suzuki Bandit wheel has an offset hub, so with the help of my wife’s grandfather and his lathe we made custom axle spacers to line up the sprockets and center the tire in the swingarm. With wider wheels installed at both end I mounted some sticky Michelin Pilot Sport tires, 120/70-17 up front and 160/70-17 in the rear. Then I adapted a pair of CBR900RR rearsets and modified the shift linkage with a cut off GS500 shift pedal, an R1 shift link, and a heim joint.
In search of more power I drilled the ignition rotor five degrees advanced, a home machinist trick for some free horsepower learned on the GSTwin forum, instead of buying an expensive aftermarket ignition advance. The Suzuki’s Mikuni carbs were jetted and capped with pod filters, and a full Vance & Hines Supersport exhaust system helped the little twin breath easier. Those simple mods were good for six horsepower, which is a decent jump when you’re starting out with 39.
By this point I had been riding and wrenching on the GS500 for years. It was on at least its second fuel tank and I’d experimented with a dozen handlebar and headlight/fairing combinations before landing on the GSX-R 600 front end with Vortex billet triples, clip-on bars, and an Acerbis Blitz headlight and fairing. A carbon kevlar solo seat also became a permanent fixture. It was finally time to tie everything together cosmetically. I dropped the tank and plastics off at Wicked Paint in Virginia Beach and let them do their thing.
At times people gave me a hard time about putting so much effort into a lowly Suzuki GS500. You can polish a turd, they’d say, but it’s still a turd. By the time it was done most of those same guys, now unable to recognize the bike for what it started as were mostly curious and complimentary. In the end, I accomplished what I set out to do – build an attractive, functional, inexpensive street legal track toy. I was able to take a bike that I built at home and thrash it on the track on Saturday, then ride it to work on Monday. That was pretty cool. I’m not overly sentimental about most of my vehicles, but this is one I definitely should have held onto.
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As the saying goes, there’s no replacement for displacement. There’s truth in that statement, which is unfortunate when you’re working with 487 air cooled cubic centimeters.
We didn’t have pre-modification baseline numbers for our 1993 Suzuki GS500, but a little research revealed the average stock GS500 puts down about 39 wheel horsepower. That’s not a lot in comparison to the average modern sportbike, but it is enough to have some fun without getting yourself into a whole lot of trouble. That said, after completing a bunch of work on the bike we were hoping to put down a few extra ponies and fine tune our Suzuki GS500 on the dyno at D&D Import Cycles.
Suzuki Gs500 Ignition Advancer
Prior to visiting the dyno we had opened up our Suzuki’s factory Mikuni carbs and re-jetted them with a stage III jet kit and pod filters. The ignition was also re-drilled with a five degree timing advance, and we installed a full Vance & Hines Supersport exhaust system.
With the bike warmed up to operating temperature and strapped down on the Dynojet 200, dyno operator Jerry Peak shifted the GS500 up through the gears to an aggressive fourth gear roll on the throttle. Fourth gear was used for the power pulls because it’s the point at which the ratio between the rotating dyno drum and the Suzuki’s rear tire is closest to 1:1. The base pull calculated 44 horsepower at the wheel – already a very good improvement from the stock estimate. The graph also showed the Suzuki twin to be running rich.
Peak suggested replacing the 134 main jet that was installed as part of our jet kit with a smaller 124 main. The smaller jet leaned out the Suzuki’s mixture a bit more than we’d like at low rpm, but kept the twin burning at an ideal air/fuel ratio of about 13ppm in the operating range of the power band. On a carbureted engine compromises like this are often an unfortunate necessity and a lean condition is far less dangerous at idle than it is at WOT. The smaller jet also provided a 1.1 horsepower gain for a peak 45.1 horsepower at 9,200 rpm, and cured an off-idle stumble. The power curve recorded by our GS500 is pretty smooth, but had there been any sharp peaks or valleys the dyno would show us where they were so we could attempt to tune them out.
With 45.1 horsepower at the wheel I’m not likely going to run down a Ducati at the race track, but the extra power combined with an improved throttle response, better breathing, and linear power delivery sure makes it fun to try.
Gs500 Ignition Advance Transmission
D&D Import Cycles is located at 1038 W. Little Creek Road in Norfolk, VA. They specialize in sales, service, and performance tuning of import motorcycles.
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