Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
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f White Brothers Yamaha YZ250 Novice Modified Production Flat Tracker Our first competitive outing taught us that our yz is already competitive with 250cc flat trackspecific equipment, and thus should wort< well againS1 with bikes of the same origin. In the future, we plan to experiment with special rear tire cuts and flat track-style handlebars In order to get the bike to wort< even better. I::;;.------------------., _..;~iii:=~;..;. _.......... _ which mimics the dimen· -.............. sions of the shock seal head that would normally ride on the circlip that holds everything together,· Searcey said. "We thought about using an internal spacer, but that would have meant a lot of machining to match the holes where the shock oil runs through the body, and it would have added to the expense of the modification significantly. For most applications, the external spac· er will work just fine.· both loved it! All that was left was to ride the thing and see if we could make it actually turn a corner. After running six abortive laps for a sound test on the pocked·up Temecula Speedway 3/8 mile near Lake Elsinore, Califor· "Different applications may require different modifications," Searcey said. After rebuilding the shock and loading it with Spectro Very Light· grade shock oil, Searcey turned his attention to the forks, which were easier yet. He simply followed the time· honored way of limiting travel Golden Rules By contrast to the "run what ya brung" guidelines for the Open and Open Vintage classes in the e·moola.com West Coast Flat Track Series, the 250cc Novice Modified Production class will be govemed by the following strictly enforced rules If you have any questions pertaining to the class, contact Gene Romero on the e·moola.com West Coast Flat Track Series hotline, 714/529-6054, or e·mail him at gromer0333@aol.com. by installing six-inch topout spacers and corresponding six· inch .46kg springs to reduce the total travel to six inches in the front. In fact, the entire suspension makeover took under two hours once the math was done. But while the process may sound like child's play and can be done inexpensively, Searcey did stress that they should be carried out by an experienced sus· pension technician. "This is basica lIy a kit, but it requires installation by a qualified technician," Searcey said. "These mods are something that we will only perform in· house, and we basically throw in the kit as part of the cost. These changes go way beyond a sim· pie oil change.· Even so, when Searcey was done, the retail pricing for the work was a paltry $358.99, and Searcey claims that he can similarly convert the sus· I. Any OE production·framed 250cc motocross or off· road motorcycle is eligible for com· petition, regardless of model year. In keeping with the low·buck premise of the class, frame modifications (such as rake alterations, swingarm shortening, etc.) are not permitted. 2. The engine must carry its OE displacement of 250cc (stock overbore allowances okay). Stroked 125s 175s 200s or anything eise that you can think of are not permitted. 3. Motorcycle must retain the appearance of an OE motocross or off· road machine through the use of OE or equivalent aftermarket plastic and seat. FTont fender may be removed. 4. Motorcycle must retaln OE or equivalent aftermarket 18-lnch or 19-inch rear rim and OE or equivalent aftermarket 21-inch front rim. Hubs must be OE or equivalent after· market items. Spools or hubs modified for qUick·change gearing are not permitted. 5. Motorcycle must reta'in OE or equivalent·sized aftermarket rear brake system. 6. Front brake may be removed· and must be disconnected· for oval track races. OE or equivalent·sized aftermarket front brakes may be used in TT events. 7. Only "Class C· rear tires will be allowed. NO rear knobbies permitted. OE or equivalent front 21-inch knobbies are allowed but not required. 8. Standard motocross modifications, such as aftermarket pipes, reeds, carbs or carb mods, shocks and/or suspension work, etc. are allowed. Mufflers Are Required. 9. Front and rear suspension may be shortened through the use of topout spacers. linkage and/or springs to make the machine more compatible for dirt track use. pension off any 250cc motocross or off· road bike for under $500. APRIL 12. 2000· cue • the motor on the larger tracks that the West Coast Flat Track Series vis· its. Then Jones got really wacky with the grinder, trimming our plastic and adding some dirt·track style side panels along with a White Brothers graphics kit and Tag handlebars, which replaced our bent stockers. Okay, so maybe he went a little over· board, but these changes made our YZ scream "dirt trackl" After Romero inspected the bike, he said that it really captured the spirit and flavor of the class in which it will be raced. We Searcey also told us that we were fortunate in that the KYB shocks on the Yamahas tend to have a lot of external threading on the preload ring, which meant that our stock spring would not have to be replaced with a shorter unit. 30 The only other immediate changes to the bike came when Jones got hold of it. First, he removed any superfluous items, such as our entire front brake assembly. Then he mounted a 19-inch Contintental Mile· stone CM5 "Class C· rear dirt track tread to our stock rim· thus complet· ing the only mandatory modification to make our motorcycle eligible for the 250cc Novice Modified Produc· tion class. Although class rules allow the use of a front knobby tire, Conti· nental sent us their Enduro Pro 90/90-21 Super Motard·style front tire to ensure good grip when pitching the bike into the turns. Jones left the stock YZ engine alone but added a Bill's Pipe exhaust system in the hope of coaxing a little more overrev out of 10. If it doesn't say you can, you can't! e n _ wv s nia, and then s ending a little time on a bone·dry version of the speedway bullring at hotshoe god Ken Maely's ranch just up the road in Corona, we weren't really sure what to expect when heading into competition at the season·opening round of the South· ern California Flat Track Association series back at Temecula the following weekend. Well, okay, a day's worth of testing at the same track told us that the bike could use some flywheel weight, so we put in a call to the folks at Steahly Off· Road in Medford, are· gon, and had them overnight us one of their l3-ounce flywheel weights for the YZ. But we never did get to test the change before heading out to the track for the race. Despite the fact that it was a day event and the track constantly changed, it took no time to get used to the YZ, and during practice I was instantly able to back it in every bit as hard as the specially framed bikes that I would be facing in the 250cc Amateur class. But practice is one thing. I was gridded in the middle of the front row for our heat race, and I wasted no time in grabbing the holeshot in front of the other half dozen or so bikes on the track with me. All right! Every· thing was going fine as I dove into