Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/125630
.', ,. Setting Up a Yamalta D11-8 for Desert COllpetition Our d••• rt 1••1., .la.1I • lilt I. Mojava .and 10 try oul .qulpm.nt addilions and modlflcallon•. This Yamaha Is rae. re.dy. By Dick Wright The ideal way to buy a competition bike is to go to a dealer and buy a new one, then have a good tuner set it up right; and that is just what I did last month. Before I decided on a 250 Yamaha otI, I tried out many dlfferent bikes out 10 the desert. I found that the Yamaha had the ease of handling and the feel and lightness that I was looking for. The starting and sh1ft1ng is out of sight; just a quick kick, an easy shift down, and you're away, The power range on the DT1 after a few goodies are added is as good as any 250 out there, and with a little effort it can be better. McCORMACK INTERNATIONAL MOTORS INCORPORATED , ~! ') .... " :,'y ~~-"'" ~-:.:.*' '....,/,:'. /-...:.....,::. ·~:1'oJI·A"'" P.O Box 1091O.5anta Ana. Calif. 92711.540"9944·654 Young Street The crisp, clean air of the early morning is calling. Blue skies above. Silent save for the song of your Zundapp cracking across the desert, alone and moving! That's what it's all about. Out in front! Freedom aboard the toughest, best handling 7OOcc alive. Proven again and again against the world's best. Zundapp I.SD. T., the winner: World trophy winner again in the '68 six-days trials. The best bike around for the guy who beats the bush but needs a street bike, too. The perfect medium: wind-in-the-face fun and street legality. Rugged, reliable with quality, craftsmanship, detail and design that only the Zundapp International Six-Days Trials Replica can give for the money. Really, there's just no comparison with other bikes. For around $555, you can't afford to ride anything else. Zundapp, the winner. All the rest are second best. Zap! ., R.IIla, lhan fully Gyt Killed, Ihls DT-1 is modlfi.d for more spa.d wilh Ih. tradablllly of. &ood desert sl.d. I contacted B1ll Butler of Granada H1lls (Calif.) Cycle and arranged to buy my new bike and have him set it up. We didn't use the full Gyt Kit, as I feel it's too pipey. First we pulled all the lights, speedometer, and 011 tank off, and then removed the stock cylinder block. B1ll nine-ported it, matched up the intake and exbaust ports, and then put on a 30mm carburetor with a 230 main jet 10 place of the 24mm carburetor (do remember to put 10 a bigger main jet when you remove the oil tank and mix 011 with gas). The Gyt Kit head was then put on, with the 8.1 compression which is very safe, and the stock air cleaner was left on. B1ll made a new expansion chamber with twin stingers, which is very functional and gives a good, wide power range. A compression release was added 10 the extra plug hole, and a thirteen-tooth counter-sprocket was put on 10 place of the stock fifteen-tooth. There are a couple of reasons why I decided aga1nst the full Gyt Kit: It will come on at about 4500 RPMs and shoot up to about 10,000 right now, and you have to be a top rider like Mike Patrick to be able to use that kind of power range. Patrick does run the full kit, and, has changed the expansion chamberbytaklng off the 3/4-1nch stinger and welding ona 1-1/8 inch I,D. stinger about nine inches long, giving him a little better tor.que. This set-up takes a little getting used to. Another thing to be considered is that the Kit cylinder is chrome-lined, and when you stick them ~, that is the end of it; tbey can't be rebored, whereas a modifled stock bluTel can be. My bike was readY in aboutf1vehours, so Saturday I took it out and ran three tanks of gas through it at 16-10-1, then packed it up to go out to the SpokeBenders European Scrambles. It was a Le Mans start, and the bike began on the first kick. A quick shift down, and three speed shifts UP to fourth gear, and I was on my way. The bike had plenty of pressure and everything was going great until I hit the big ditch two mlles out; after I got up, it came to me that the stock suspension was great if you didn't hit the big ditcbes too fast, so back to the garage I went and pulled out the stock front springs with the two-and-a-half-inch tube spacer. In their place I 1nsta1led a set of non-progressive Cer1anl33-pound springs and a one-inch booster spring, and then seven ounces of 30-welght detergent oil. Cer1anl shocks were added on ·the rear, with seventy-pound springs (Girlings will also do'the job). After four races, the bike was taken back to B1ll Butler for a check-out, and we found that the tlm1ng was off only onethousandth, and the sh1tt1ng adjuStment was off one-sixteenth of an inch. After we tightened the bolts on the rear sprocket, the bike was again race-ready. To sum it up, the DT1-B is a good play or street bike, and can be converted to a racJDg machine in about five hours by someone who las the know-how. The handling is light to the touch, and it will work with you, not f1ght you. I found that I could go into the hole faster because of the haDd11ng qualities, and come out faster due to a good power range. In add1tlOn, the price for the race-readY machine was DO more IlIaD any other raoe-readY take, and less tIIaD a COllPIe at them.