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/126023
approxima t io n. we 're using 13 0 pound sp rings and Red Win g's No. Th ree da mp ing uni t (n o t normally reco mmended ex cept for racing) to cope wi th the ex tra leverage of the '75 swi ng a rm . It's worth a try . Mechanically, th e electrics transfer easily also . The TS 4 0 0 's external ro to r exciter and black b ox ar e a bolt-in swap for the TM 's in te rnal ro tor excite r a nd black box. The rest of the wiring harness is lai d along the bare frame. connected up by co lo r co de, and Tv-wrapped judiciously . The trick is to make wiring that Was assembled for a different frame hang kink-free on the motocrosser. The TS400 battery is located transve rsely in the MX fram e. slung fro m fabricated angle supports in the narro w spa ce be tween air box and rear tire. To make it fit. the rear cover of the ai rbox had to co m e off, which means no lo nger can th e bike fo rd three-foot-de ep watercr ossin gs. T sk . T o clear the battery . the stock TM 400 oil inj ection tank had to be sp aced ou t on three-quarter in ch a lu m in u m don u t sp acer s. usin g 6 x 70 mm hex bolts in place of th e stoc k ones. The lower battery b o x bracket is benfiip to co n tact th e lower wal l o f t he airbox, so once agai n th e battery has th ree p a in t sus pens io n . all rub ber-isol ate d . Th e ign it ion swi t ch will go o n the fork cro wn behind the in stru m en t (s) which will need a fab ricated bracket. Als o to be made. a new lower splash guard between th e battery an d re ar ti re . The rearse t footpeg m ounts we re m ade from 7/8 inch mi ld ste el han d lebar st o c k and :\IIG-wel ded to the frame (which is also mil d steel) b y a very good fr iend wh o also d oes neat m etal sculptu re . While we were at it. he rein forced th e fra m e near the footres ts . Foot res t stubs. iden ti cal fo r both sides , we re cu t fro m o ne-inch b -u-, Di mensions o n re a rse t sub frames and stubs appear in Figure I. TI, e st ubs we re design ed so th at co n tro l pedals fabricated on re amed han dl e bar stock would turn freely o n th em , re tain ed by a heft y circl ip . 111e inne r e nds were a han d -p ressu re fit into the o pen ends of the sub frames , a nd we re wel ded in place. Th e m illed o uter ends take t he st ock foldback footrests. The old footrest stubs on the frame were ground flush . We're still diddling with the ca n tr oIs and lin kages. T he unlovely pipe is a center bleed de sign. tu ne d fo r a 50 0 RPM hi gher peak th an stoc k. Ir's an o the r d eliberate experim en t. cre ated to te st the following theo~ies: 1) That th e cen te r-bleed gives enhanced wave reflection in the m id -range with n o lo ss of top end. p lus it helps us tu ck the pipe in better. 2 ) That the Murphy muffler. operat ing at op timum power : range , actually d ra ws th e pressure in the cha m ber down en ough to significantly lower the speed of sound in the chamber. This effect should yield a shorter-than-formula pipe that works. The engine is otherwise stock and will remain so for awhile. . That's where we stand at th is writing. TI,e main reason the bike has n ot run by now is the au thor's stu bborn de termination to c rea te a fibreglass ta nk and seat fro m scratch. In retro sp ect . we should have scrounged th at as well. b u t th ere 's to o much ti me an d swea t sunk in the mold plugs to q uit now. Besides, it's an interes ting shape, an d it sits very co m fo r ta bly in mock up . The pr oject is at that stage where the temptation to rush and get it rideable (a t th e risk of sc re wing something up ) is • ba rely re sist able. But we're holding. ~LONG BEACH HONDA WIN! These are the products that Hi-Performance products available for Honda XL-350 ' 1. 410cc Piston Kit Inc. Rings. Pin. Clips. & H. Gasket $49.95 A. Piston Only $3 2. 50 B. Rings $ 9.9 5 C. Pin & Clips $ 3.9 5 D. Head Gasket $ 6.9 ~ 2. Hi-Performance Ca m 529.95· 3. Hi-Performance Cam lIardweld $49.95· 4. Special Hi-Performance Needle Bearing Cam $129.95 5 . Racing Valve Springs $24.95 6. Special 36m m Carb ure t or $48.95 $ 5.95 7. Thro ttle Assy . (for 36m m Carb.] 8. Throttle Cable (for 3 6 m m Carb.) $ 3.0 0 9. Shim Kit fo r Std. Valve Springs $ 4 .95 10. Special Ported & Polished Head $85.00· 11. Special Ligh t Flywheel $29. 95 $26.95 12. Special T uned Hi-Pip e (E nd uro or MX) 13. Sp ecial T uned Lo w- Pipe $26.95 14 . Megaphone Silen cer (fo r above pipes ) $ 26 .95 15. Spark Arrest or/Silencer (for above p ip es) $ 19.95 16. Floating Rear Brea k Assy $45.00· 1 7. Heavy Du ty Sk id Pla t e (A lu m in u m) $4 9.95 18 . Lighte ned Ro cker Arms $12.00· 19. Special Tach . Drive Replacement $ 8 .9 5 20 . Speedo Drive Plate & Spacer $ 7.95 21. Alu m. Wheel Beari ng Spacer S 6.95 2 2. Special Hi-Performance Racing Ge ar (3 rd Mainshaft & 4th Countershaft ) $ 79 .95 set 23 . Special Racing Frame, 4130 Chrome-moly (Cust o m Built to your spec. ) 5529.00 24. Modified Betor Forks with 8W' Travel $199. 9 5 from 579.9 5 25 . Sp ecial Ra cing Rea r Sh o c ks 26. Racing Oil Co oler Kit $54.95 2 7. Titaniu m Valve Spring Retain ers $ 24.95 28 . Sp ecial Big Bor e Copper He ad Gas ke t $ 8 .95 29. Compression Rel ease (Com ple te with Lever & Cab le) 5 24.9 9 3 0. Raci n g Cl u tch S29.9 5 Let us buil d you a winn er to o! Order T odav Send c heck or m onev orde r T he cente r-bleed pipe is so ho m ely it's jus t got to wo rk. Feet on im agina ry pegs, gr inding shop owner Fred McCall checks out riding posit ion with mockup f uel tank in place. " N ot bad, but it needs so me padding in the seat .. . " , Ca liforn ia reside n ts add 6 % sales tax LONG BEAC H HONDA 5 1 15 Atl a ntic Long Beach. CA 90 80 5 2 13 -4 2 3- 143 3 * Exchange Price - Core must accompan y ord er or add 'I. charge wi ll be made ---------------------------------FREE 10 point safety check ROBERT M. LAW is in terested in h elping yo u get yo ur YAMAI·IA Motorcycle read y for the Fall Seaso n. With th is coupon yo u can save $7 .50 on the labor charges for a TUNE & SERVICE and /or S7.50 on the labor charges for INSTALLING NEW FO RK SEALS. A' Yamaha Special ends January 31, 1976 o .' N Robert M . Law 239 Anaheim Blvd .• Anaheim, CA Phone 714-533-1309 discount ~~52:t:>t mon~y! coupon ---------------------------------Close-up of what you can do with leftover handlebar stock on a m ild steel frame . The stock frame re in forcement plate is only tack-welded, so we ran a bead all the way around it , since it will now be carrying the rider's weight if he chooses to ride standing up. Batte rY was a tight squeeze in the narrow MX chassis, but it fit. We t ried to keep it s weight as low in the frame as possible. ~DDm!Dfufi 1IDfi[p~ illfifu@ ~n@ New TM 100 New TM 125 New TS 125 New TM 250 New RM 125 New RM 250 New RM 370 New TM 4 00 $ $ $ $ 590 590 585 790 s 715 $1090 $ 1209 $ 795 Similar savings on all Enduro & St reet models ~DD~ill D I1~ l]]®rnc9Jffi 0 ~mZhDDlli.ft . . 9735 Lo ng Beach Blvd., So ut h Gate, CA . . • 213- 564-5666 Open 9-6 Mon .-Fri. • SUZUK I Parts & Accessories SUZUKI 1 9