Suzuki TM400 1971-1975

I have put some Suzuki TM 400 brochures and facts on this page. I would be grateful of any contributions — sales brochures, magazine ads, magazine articles, pictures, specs, facts, corrections etc. Please scan the material in JPEG format (large enough that all the details are visible) and send them to me. Please tell me the source and the publication date if possible. If you send me pictures of your own bike, please follow these instructions.

A detail from a 1972 TM-250 J & TM-400 J brochure. The guys at the picture are American motorcross champion John De Soto (right) and his brother Ron. Click for full image. SUZUKI TM MOTOCROSS MODELS INTRODUCTION Joel Robert was Suzuki’s first Motocross World Champion in 1970 winning the 250cc class and after this success Suzuki introduced a production motocrosser. The Suzuki TM400R was manufactured for the 1971 season and coincided with the signing of Roger DeCoster in October 1970. The following information traces the history of the Suzuki TM range and were possible have included original Suzuki brochures to help people identify and restore TM’s. These early Suzuki motocrossers are now a collectable machine as well as a reliable and competitive bike in the Pre-74 Classic Scramble events.

1971 Suzuki year code: R

Nicknamed the ‘CYCLONE’ the TM400R was the first Japanese production motocrosser to be mass-produced. The huge 82.5mm bore piston turned out 40 bhp at 6,500 rpm and along with the fan-finned cylinder head it had a compression ratio of 7.3 : 1. The crankshaft halves were not full circle type as fitted to most two-stroke engines and made the engine rev more; one answer was to fit aftermarket flywheel weights made by Competition Dynamics in the USA. The clutch was based on the T500 road bike with seven fibre drive plates and seven metal driven plates it was operated by a rack and pinion type mechanism. A five-speed gearbox provided transmission. Carburation was provided by a Mikuni 34mm carburettor featuring a fuel trap around the main jet, developed to keep the float level more constant by keeping the fuel in the trap area. Air filtration was by a large capacity, dry paper element housed in an airbox under the seat. It had Suzuki’s Posi-Force oil injection rather than the usual pre-mix used on most competition bikes of the time, the two stroke oil tank was situated behind the right hand number plate. Kokusan Denki provided the sparks with their new pointless electronic ignition (PEI) that had an automatic spark advance curve from eight degrees at 2000 rpm to 28 degrees at 5000 rpm. The front forks had seven inches of travel but this wasn’t all used because the standard springs were to heavy. Rear suspension also was very stiff and only provided four inches of travel. It was very powerfull and unlike the ‘Works’ bikes of DeCosters it didn’t handle, infact it was totally different to the factory racers and more suited to the open type racing or desert races in the USA. For the more serious competitor specialist frame manufacturers produced frames to help the handling problems, Eric Cheney in the UK and Red Line Engineering in the USA were two such companies. Folding footrests were made from fabricated steel. The fuel tank had a steel twist type cap with air breather and badges that screwed on, the colour was Chrome Orange (Suzuki colour code 184) with a black stripe running under the badge horizontally. Check out the competetion test (against Maico K400) in Cycle Magazine May 1971

1971 TM-400 Cyclone magazine ad from USA (detail). Click for full image. The rider getting a trophy from a girl in a bikini, is Jim Odom.  He was a dirttrack racer in southern California in the 60's and 70's. (Thanks for the research, Scott Andersen!

1971 TM400R sales brochure (two pages). Click to enlarge. These scans was sent to me by Markku Nissilä from Finland.

1971 TS250R and TM400R magazine ad from Sweden (MC-Nytt 8/1971). Click to enlarge. There was an interesting article in the same magazine of the Suzuki history (1909-1971), from the '71 point of view. Naturally the magazine author couldn't predict the introduction of Suzuki's four-stroke macines a few years later, and he couldn't think it was possible for Suzuki to keep up expanding and making better and better motorcycles in the same furious rate that it had been doing for the past 20 years. He also predicted that Suzuki and Kawasaki could join their forces, he wasn't sure if there were market enough for four big Japanese motorcycle manufacturerors in the future. Today, over 30 years later, we know that Suzuki, as well as Kawasaki, Yamaha and Honda has survived and kept on making better motorcycles and kept on growing.

1972 Suzuki year code: J

Virtually identical to the 1971 model apart from the colour which was now Philolina Yellow (Suzuki colour code 163) so it was more in keeping with the ‘works’ bikes.

1972 TM-250 and TM-400 brochure page and a 1972 TM-400 magazine ad. Click to enlarge. The ad on the left: American motorcross champion John De Soto (right) and his brother Don Ron.* The ad on the right shows a group of five riders, all on different bikes.  The Suzuki rider is John DeSoto, the Flyin Hawaiian.  Check ot the pineapples in the stripe on his leathers.  The Maico rider is Jim Hart and The CZ rider is Jim Connley. (Thanks for the research, Scott Andersen!) *) Correction: Dan Murphy spotted the typo: “I came to it to look at the old TM 400 Cyclone brochure. The picture shows a 250 & 400 with John De Soto and his brother Ron (you show it as Don). The De Sotos were friends of mine during that period. John and Ron now both live back on Hawaii.  I just spoke to Ron a month ago. Hope this helps.” Thanks, Dan!

1972 Suzuki TM400J Cyclone sales brochure. Click to enlarge. The scan was sent to me by Gary Pedersen.

1973 Suzuki year code: K

The '73 TM400K was very much the same as the '71 and '72 models with some minor updates. The air filter was now a more washable foam element. Footrests were now cast steel folding type. A different frame, forks, suspension units and swinging arm were all fitted in an aim to help the handling. The fuel tank had Suzuki stickers instead of badges and a blue/white stripe went round the back of the tank where the letters TM appeared.

1973 TM-400K sales brochure. Click to enlarge.

Another sales brochure from the same year.

1973 magazine ad: TM-125, TM-250, TM-400 (two pages). Click to enlarge. The rider on the left in the right side ad page is Suzuki factory rider Richard Thorwaldson. Thanks to Scott Andersen, Texas. Here's a scan from the 1973 TM400 parts manual.  It may not be the best photo of the model, but interesting, with three different model years on the same page.  It really shows how different the 73' model is from the two earlier years. Thanks again, Scott Andersen!

1973 USA full line catalog pages: TM-125, TM-250, TM-400 (three pages). Click to enlarge. This scan was sent to me by Gilles Nault, Canada. Here's more scans from the same catalog.

1974 Suzuki year code: L

The '74 TM400L was much the same as the '73 model, the L had straight type finning on the cylinder head and internally had been altered to reduce the compression ratio to a more useful 6.8:1. The front sprocket cover was now fitted with three holes for mud to escape from rather than the earlier type that had two diagonal slits. The exhaust system now had a rear silencer fitted to help muffle the noise. Suspension units were a newer type. The fuel tank now had dark green/white stipes that did a U round the rear of the tank

1974 TM-400L sales brochure. Click to enlarge.




1974 magazine ad: TM motocross lineup, two pages. Click to enlarge.



1975 Suzuki year code: M

Concider yourself lucky if you find a 1975 TM400 - they are very rare. Not many bikes were made because the RM's were already coming down the assembly line, and Suzuki knew the TM's wouldn't sell with the new bikes available. The 75' bikes are actually very different from the 74's, although it doesn't appear to be so at first glance. Look at how much farther forward the rear shocks are mounted on the frame and swing arm. They handle better than the earlier bikes.

1975 magazine ad: TM-100, TM-125, TM-250, TM-400. Two pages. Click to enlarge.




More: 1971 TM400 Cycle Magazine test

More: Suzuki TM series

More: All Suzuki models

Sources: Crooks Suzuki, Markku Nissilä etc.

This free site is managed by Jarmo Haapamäki.
If you find this site helpful, please leave a donation for Jarmo
so you can enjoy the spirit of giving too.

Came here from a search engine?
Click at the home button below to get to the main page with frames.