Cycle News - Archive Issues - 1970's

Cycle News 1975 11 25

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/126017

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When I first saw the "Phantom" on the desert horizon he' was only a tiny dot leading a rooster tail of sand and dust. Being out in the middle of one ' of California's high deserts all by myself with a wine bag hanging from my shoulder and some food in my jacket, I suddenly noticed how alone I felt. It was 40 miles back to camp. So I said out loud, "Humm .. . someone to ride with on this lonely, winter's day; he'll be spittin' rocks when he comes up against me and this big machine." As the orange blur came nearer, it was interesting to watch the tremendous dust cloud try to catch up to its rear wheel which was tracking straight and true over rocks, sticks, sand and cactus. At that point, my over-confident self signaled the rider down. There must have been a normal face behind that smo ke colored shield because I could hear heavy breathing from his cross country workout. "Let's ride together; we seem to be ·th e only freezing fools in this whole desert," said 1. The strangely quiet, faceless helmet moved up and down for yes. Then I noticed his machine. There was no factory name on it, only some neat, black letter reading "Turkey 400." The only things that didn't look stock were the vertically mounted Betor shocks. The unique exhaust sounds caught my ear; and I noticed it took some careful follow through and a little concentrated strain for him to get the turkey going. Then the hidden face yelled over his engine and said, "That $ 1600 racer, will nev er stay with this $500 turkey." And then (Are you ready for this line?) I retaliated with "You11 never take me alive! n I'll skip the rest of my tale because it's too embarrassing to relate. But I will say that he outran me over the dry lake, over a four mile stretch of whoop-de-doos cross country, and that turkey went into the jeep road turns with my machine and sand blasted my new goggles coming out. Need I say more? That night I couldn't sleep. For days after I had returned to the land of concrete and smog, those figures $500 versus $1600, echoed through my brain. I called cy cle shops, checked the newspaper ads, and chased down various used bikes until, after two weeks, I found a turkey like that of the phantom. It was an immaculate 1971 Suzuki TM 400. Its owner traded it in on a 360 Bul and if he could ride his old 400 now, he would hate himself. I bought it on blind faith for $425. To show you what they can go for, I have a friend who bought one for $350. Everyone knows that the Suzuki TM 400 is a turkey. Most of the dirt bike mags tell how bad they are, but the objections have never been over lack of horsepower or torque. The justified complaint has always been terrible handling. Keep this quiet, but since most of the bike mags have made the TM 400 a public joke, a used one is worth very little. And you get a lot for a little. The purchaser of a 1971 or '7 2 TM 400 receives horsepower an d a bulletproof engi ne, transmission, and clutch' (notice that I left out frame; you occasionally have to reweld the quarter moon shaped plates which support the bottom, rear motor mount bolt, if they try to crack away from the frame). You too can own a "Turkey 400," go very fast, have better than average handling, and save hundreds of dollars on your next dirt bike. I know it sounds hard to believe. Read on. I started with the forks, installing a Trickit kit, a pair of Suzuki TM 250 springs, and 190cc of 30-weight oil. I ended up with over six inches of travel with no bottoming. Next I went to the rear suspension, extending the swing arm two inches. The '73 TM 250 swing arm is two inches longer than the '71 -'72 TM 400 swing arm, and it will bolt up; so you can either buy a used swing arm or weld two inch spacers into the original. Then I made two steel plates to extend the length of the upper side of the swing arm. After that, I went to a friend who has an arc welder and we welded the plates on as extensions of the bottom shock mounts. 1 measured three inches forward of the original bottom shock studs to obtain vertical shocks. The vertical position can be determined by hanging a weighted string from the top shock stud. The final touches for good handling will be your choice of good pegs, bars, and tires. I like a 4.60 X 18 rim protector with six pounds of air and a 3.50 X 21 with 15 pounds of air. The above modifications will let you stay on the turkey long enough to find out what 40 factory horses feel like, and you'll enjoy the handling. In the future, I want to experiment with Betor or Ceriani forks, and a monoshock rear suspension, because with my newly reworked engine, I occasionally outrun my modified stock suspension. As to the engine modifications, let me warn you now that if you can't control Pontiac type torque and small-block Chevy type horsepower, then leave the following engine mods to the quickies. As stock engine, in good shape, is enough for many riders. Just be sure that, in either stock or modified form, the engine has a two pound flywheel in order to give smoothness and controllability. The engine should be the 1971 or '72 TM 400. If the piston and rings are good, you are holding a great deal of cheap, potential horsepower. I only have a total of $505 in my "old Suzuki. " The internal parts of my engine were good, so the only thing 1 had to buy was a barrel gasket. The head gasket can be cleaned, heated to a glow, and reused (unless blown) . Disassemble the top end of your toy. Observe that the barrel gasket is wider than the two transfer parts on both sides of the barrel. Take a hacksaw and cut the slots straight down to match the barrel gasket for each set of parts on both sides. File off the rough edges. Next, fit the piston in the barrel, properly oriented, so that the piston slot is flush with the barrel slot. Then scribe the new wider barrel slot positions on each side of the piston. Now carefully, with a rotary grinder, grind away the piston to match the barrel. Then take the piston to a machine shop; or if you are ,!ood with a hacksaw, cut .080 inches (2mm) off the rear piston skirt. Polish the piston's dome with different grades of fine sandpaper in order to retard carbon builtup. If you are able to keep the old piston, you should scrape the carbon out of the ring lands. Clean the piston, pin, rod bearing, and rings. Reinstall the rings and assemble the piston on the rod; you're finished with it. Here's where the sweat starts TURKEY 400 Of , HOW TO MAKE $500 BEAT $1600 BY CHARLES P.SUGG I II, I 12

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