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/125800
THE ECONO-CROSSER ·REVISITED c. " '" '" w ~ Z W ...J U ~ U The author leads Br~tt Greenwood on his econocrosser in an MX at Bisbee, Arizona. Check the smooth, even track surface. - Photo by Dan Chandler. by Kent Nicholls For over a year and a half, I campaigned one of those incredibly heavy and evil handling DT-I's in everything from IT Scrambles to desert races. The only .thing that ended our relationship was that some nefarious person ripped it off from my garage. But the thing had one outstanding feature - it never broke, wNch was amazing considering the amount of thrashing I put it through.. The old campaigner even survived the 1970 Barstow-to-Vegas, not even fouling a plug. Right after losing the bike, I moved to Tucson, Arizona. Soon I got very horny to have another bike, so I began to look around. As I was looking, a tiny, high-pitched voice kept reminding me how dependable the old DT-l was. So gang, I ended up with one of Yamaha's (then) new motocrossers: the 250 Econo-crosser, (A name, as you may remember, affectionatly given to the RT and DT-2 MX's a few months back by Cycle News.) When I took delivery of the shiny new silver and red machine from the good guys at Eastside Cycle in Tucson, I ran smack dab into the Yo u-Iove-your-damn-newtoy-more-than-me syndrome from my girlfriend of that time, which I am told is fairly common amongst motorcycle racers. Anyway, the next morning, Son of DT·I and I beat the sun out of bed being that I was hot to find ou t if the DT-2 re.ally handled as good as everyone MlD-OHlO MX PARK, Sept. 6, 1972Rupp Manufacturing Co., maker of sport vehicles, has now entered the field of real, grown-up motorcycles with the new Rupp 125cc motocross bike. A pro lO type 125 was unveiled to the public al Mid-Ohio Moto-X Park, on Sunday. Sept. 3rd. This new bike will go into production in December of this year at the Mansfield, Ohio plant and be available for the 1973 racing season. The performance of this bright red beauty during the motocross at Mid-Ohio was outstanding. A drizzle during the day kept the track sticky but when the 125 class took off from the starting gate, this new Rupp was number one around the first tum. For power, the Rupp-Rider aboard Ilad plenty as he blew off the Pentons and Huskys during the ten minute moto and crossed the fmish line first. In the second moto the story was the same with the Rupp bike running away from the field of other riders. Tills bike definitely out-powered and out-handled the other forty-seven bikes in the class. The Rupp bike has a fifty-five inch wheel base, a Sachs HB" engine developing 20-24 HP weighs only 189 lbs. wet! Could this be the Great American Motocrosser? said it did. After my normal three minute break-in period, I twisted the wick to see just how fast the sucker was. What a let-down, the engine coughed, sputtered, made other assorted bad noises and died. After wiping the tears from my eyes, I pnlIed the plug cap and discovered a NGK 9ES lurking below. It just so happened that I had an 8 ES in my pocket which transformed a very loaded-up motorcycle in to the. really fast 250 that it is. Yamaha put .some nifty looking two-spring shock.s on the machine which put me on my head in short order. These units on my bike were somewhat lacking in damping. I repl!,ced them with inch shorter Konis and 80 lb. Bultaco PurSang springs. Now, I only weigh 150 Ibs. and these springs migh t be too soft for heavier riders. The fron t forks seem to be righ ton. This made the Yamaha one of the better handling 250's that I've ridden, and comparing it to the DT-l would be like comparing night and day. The only thing two bikes have in common is the name. Before I bought the bike, I read and was told that I would soon be replacing the soft alloy rims. I've had the machine now for five mon ths and they are both still fairly round. The only problem I had with wheels was that the spokes kept coming loose, especially the rear, but safety wiring the spokes where they crossed solved that problem. After eight races, the piston and ring were worn ou t. Being that I don't have endless funds for replacing such items, I did a little sleuthing around and found that Yamaha's neat new fuzzy foam air cleaner elemen t wasn't magging all the engine bound grit. So, I went out and bought a good 01' Filtron and put my mind at ease. I figure that two rings are better than one-especially if one is a Dykes type. It just so happens that the DT-2 Enduro piston has these features. It also happens that all the holes in the piston are nearly the same as in the MX piston, so I installed one in my bike. It seems to have a little more low end and still pulls just as strong on the pipe, plus it's just got to last longer. Talking ahout the pipe, I've been told that I should remove thar' 55 gal. drum that Yamaha calls a silencer and install a smaller one in it's place, they shorten the stinger the length of the silencer. But the stock device does such a neat job of removing the bark from the exaust and the bike still goes a lot faster than I do, so I left it alone. Yamaha uses a cam affair in the secondary chain case on the engine to push the c1u tch actuation rod in and out thus engaging and disengaging the clutch. Well, I found that if one doesn't keep the area around the counter shaft sprocket clean, this little cam will get dirty and freeze up. If this happens, all clutch control will come to a quick end. So, whenever I wash the bike, I spray out that area, this seems to have ended the problem. Arizona has to have the rockiest motocross courses in the world. In one race, I picked up a good sized stone in or~e of the fork tubes (lower), leaving a frightening large nick. Said nick didn't affect the operating of the forks, but to stop future happenings of this type, I made some lower tube guards ou t of Ozite carpet tiles like on the trick European factory bikes, (Neat). Ever since I began racing, I've had the bad habit of doing the Yogi Bear Stomp (Sorry about that.) on the shift lever. Like any motorcycle, the Yamaha DT-2 will only take so much of this before it breaks. It did. Luckly it was just one gear (second) and the parts are clfeap, so this wasn't as bad as it could've been. The only other changes I made were: One - I removed the oil injection because I'd rather do it myself (Mix the gas and oil that is). Two - I put Magura levers on the scooter only because I had them, although the stock levers are really first rate. And third, I installed a set of Metzeller tires because I've had good luck with them in the past. Like the levers, this change was merely shaping the bike to personal taste and not really necessary. After owning the motorcycle for a little over five months, I still dig it as much as I did the first day I got it. I feel that I made a wise investment in buying an Econo-crosser. The Yamaha DT·2 MX is not really race-ready out of the crate, but with a few minor changes, it can become a machine that is capahle of competing with Europe's best.