From the May 2007 issue of Midwest Motorcyclist^TM

We weren’t just sitting in the Lazy Boy, drinking cheap beer and watching American Idol and Deal or No Deal this past winter. No, we were braving subfreezing temperatures in the ice box of a garage in the effort to continue progress on our street motard project bike.

For those of you who missed the first series of articles about this project, we acquired a used Honda XR650L dual purpose motorcycle a couple years ago just for fun riding on some dirt roads and trails. After a brief excursion on track at a MISupermoto event in Jackson in the fall of 2005, the decision was made to convert the XR into a street ‘tard that would double as a track bike. That day at the track was the beginning experience in what has become an expensive obsession. (Damn you, Jeff Bottrell. Looking back, you were just a supermoto pusher and I was the unsuspecting, soon-to-be supermoto junkie.)

The most significant changes last year was the acquisition of 17” wheels (actually 17” rims laced to my stock hubs by Buchanan Spoke and Rim), Pirelli Scorpion Sync tires, a 320 mm front brake rotor for Supermoto Engineering and a steel-braided brake line from Russell. I also installed a 4.3 gallon plastic tank from Clarke Manufacturing and plastic front and rear fenders. To assist in improving the XR’s performance, I offloaded a bunch of weight including passenger pegs, rear seat brace, rear fender and light assembly, steel fuel tank, front fender as well as few other minor tidbits. I rode the bike at several track dates last year and was quite pleased at the bike’s performance. Rides on area dirt roads were as fun, if not more so, than the track. Clearly, the decision to covert the XR was a good one. I eventually decided that it was time to work on engine performance.

This past winter, the effort to squeeze more performance of out the XR’s 644cc, air-cooled powerplant began. The plan was to both modify the carburetor to provide more fuel flow and open up the flow of air to let the engine breath. I found a procedure on ThumperTalk (www.thumpertalk.dom) called Dave’s Mods that would apparently allow me to fulfill the first part of that plan. A Dynojet Stage 1 carburetor kit provided two main jets (160 and 165), a new needle and slide spring. I followed Dave’s directions, drilled out the slide, installed the 160 main jet and re-assembled the carb. Once the carb was re-installed, the bike started right up and started easier than prior to the mods ever since.

Next, I removed the snorkel in the top of the air box to let the engine breath better. I also cleaned the air filter figuring, what the heck, I was working in that area any way and that might free the flow of air to the carburetor.

These rather simple changes made a huge difference in the bike’s performance. From a stopped start, the XR launches, easily lifting the front tire. If I were a stunt jockey, I could probably wheelie in the first three gears with little effort. I can’t say for sure whether the bike is better on the top end but it feels like it. It seems to accelerate faster but I haven’t yet tested the top end. The only thing left to improve the air flow would be an aftermarket exhaust. This option has been on the table and off several times during this project. I want the performance improvement offered by an aftermarket exhaust but I want to run quiet. No need to draw any more attention to this middle age hooligan than I’m already getting.

Aesthetically, the only change is that the once white side panels and headlamp hood are now black like the tank and fenders. Krylon Plastic Paint seemed to work OK but we’ll see after a few outings; I’ve already noticed a few chips around the headlight.

Not willing to let well enough alone I started thinking about other things the XRStreet Motard needed. Clearly, a rear rack was necessary to carry tools, a first aid kit and other essentials. Got a gem of a deal for a black powder-coated rack on EBay for about $70. without the under-fender support, it probably won’t carry much weight but it’s enough for my current needs. Who knows what might happen during future upgrades.

Another potential problem that became apparent while the bike was up on the rack was the exposed underside of the engine. The cases were open to damage from rocks, crashes and other destructive forces on the roads and trails. A skid plate (sometime called a “crash plate” but I hoping not to use it like that) was clearly required. A few calls and bucks later and the new plate is protecting the underside of what I am now starting to call my “Adventure ‘Tard.”

Finally, a screen to protect the headlamp was installed because, well, an “Adventure ‘Tard” is likely to be ridden in situations where rocks, branches or other debris could be thrown from the road, trail or track and break that light. It was cheap, looks good and will hopefully function as planned should the debris attack present itself.

That’s it for now. As I’ve written repeatedly, I’m not much of a mechanic. My skills are improving as is my patience (Thank you, Paxil) and I’m really enjoying the work. It wasn’t that long ago that the prospect of completely dismantling and rebuilding a carburetor would have seemed daunting at best and improbable at worst. Despite the initial apprehension and few challenges, the project has come together better than I imagined.