Cycle News - Archive Issues - 1970's

Make your Ka'Wasaki Single t h e fa s t e s t on the block ... ry Scott t track. , body " ; " .'" C1. N .... Cl N N D u. " ~ w Z W .J U > U CASES T h e sam e engine cases are used for the 250 and 350. Windy is a n u t on t wo it em s of preparat ion th at must be fo llo wed fo r lo ng engine life. Deburr every thing an d clean liness . Make dam n su re th at a small piece of foreign material does not des troy, in seconds. an engi ne it h as ta ken yo u man y h ours to build. T id e and wa ter are che ap . CRANKSHAFTS Th e first step is to ta ke th e crankshaft apart. Chuck each half in a lathe , o ne h alf at a ti me in a three-jaw ch uck , h olding on th e flywh eel por tio n of th e crank with t he shaft ex tending ou t. Using a d ial in dicato r, make sure that the flywheel is tu rn ing true in th e ch uc k , th en check th e sh aft . You must start out with cra nk halves that a re dead on if you ex pect to have an assembled unit th at is straight to within .0005 . Deb UTT a ll casting flash , radius all sharp comers on th e flywh eels 'a nd use th at Tide and water; get 'em clean. RODS AND BEAR INGS S to ck FS l~1 250 rods, bearings and thrust washers are used in both the 250 and the 350 F9. Windy uses the FS U>I rods as t hey are factory slotted on the b ig end. Follow the same procedure with the rod as with all pieces, but more so . Rem o ve a ll forging lines from the outside surface of the big e nd. little end an d th e lea ding a nd trailing edge of the girder typ e r od e. Grind an d p olish carefu lly fo r a smooth overall surface that will be free of fatigue p oin ts. Caution : T ak e care to pro tec t beari ng surfaces. Take a look at the thu rst was he r surfaces of the rod 's big en d ; you will see machine mar ks. With a surface p late o r a h eavy pi ece of glass an d so me crocus cloth, lap t hese surfaces smooth . Radius th e sharp edges at the outside di am eter of the b ig a nd little ends ,005 a nd p olish . In case you were wond ering, the stroke is the same for the 250 and 350. Radius the edges of t he thrust washers and polish, and get everything clean! Before assembly of the crank, pack the big end bearing with high grade lubriplate or o il; in fact, follow the o il or lu brip la te method for the whole motor, including the transmission. It's better to foul 20 sparkplugs trying to start up than it is to wipe out an engine because it was dry of lubrication. Assemble th e crank w ith .024 sid e clearance, adjust the crank until you achieve no more than .0005 runout. , I PISTO N PIN AND PISTON Be sure that the pin is a slip flt'in ~th e • piston at room temperature. There is nothing special done to the pistons except the deburring and cleaning, rem o ve all sharp edges around the skirt and pin holes, protect the bearing surfaces. rotary vlave cover in postion and from inside the case mark th e valve cover and modify to match t he intake port. Stock FS 1M mags are used as well as stock FS 1l\1 coils . Ti mi ng is set w it h th e h ead o ff at 2.35 MM BTD C. Plugs used Ch . W' d are am p io n, in y warm s up o n L2G and swi tc hes to a colder pl ug for racing, L3G or L6G . on ly di ff eren ce b el ween th e frames is a min or o ne of steering head geometry. The short t rack frame has abou t I I'z degree steeper ra ke th an th e IT frame. The rest of the hardware choices were left up to AI and Windy. For the IT scooter Windy laced Akront rims 19" fro n t I S" rear, to stock Kaw F21l\1 hub and b rake asse mbli es wi th Kaw spokes. The front runs between a set of Bet or fo r ks, weight of fork o il and q ua n ti ty will be determined d u ring practic e. Bounce and reb o und at the rear will b e ~andled by Koni shocks. Spring rat es, like .fo r k .o il, will be decid ed du rin g practice. Windy had so many tires ready to go, and so many gear sets that even he d idn't h ave any idea what ratio or ti re they would use. so we 'll just have to wait for that info. Air to the motor is being kept clean with K & N filters , Duckwo rth chain transfers power from the engine to the rear wheel. Power for the IT machine is supplied by one o f the 350 F9 motors . The short tracker is much the sa me; Bet or forks, Ko n i shocks and Akront rims (b u t here the fr ont wheel spins o n a Bar nes spool hub wh ile th e rear rota tes on a Barnes quick switch d isc unit). \I'it h this set-up the sprocket and disc can be traded fro m side to side in just a ma il er of seconds. The calip er and hydraulic unit fo r th e d isc brake are Hurst-Airheart , One feature that looked kinda tricky was the way th e gearshift lever and brake p edal w ere placed. The Rear shif t lever is positioned abou t 3" above the b rake p edal in a vertical line on the r igh t side. How it will work is someth ing th at Dave and Gary will ha ve t o tell us. Power for th e short t rac ke r co m es from one of the 250 FS 1M power p lan ts . GAS WORKS SCOTT'S MOU NT CYLINDER Stock rin gs are used with but m ino r attention. Use a small stone and knock off the sharp co m ers at the open ends of the rings. Inst a ll the rings in th e ring groove in which t hey will ru n , check to see that the knock pin in the piston is locat ed p ro p erly so that the ring will not h an g up and fre eze, Pis to n to cy linder clearance is .0 035 fo r the 250 FS 1M and .0 04 5 for the 350 F9. Follow the long ac cepted pract ices fo r port m odific ation , using the base gas ke t as a tern p la te for laying ou t th e ',ransfer ports. Pay particular a ttentio n to that p ortio n of the cylinder skirt t hat . may . ter fere WIt h in take flow, modify in the cy linder s kirt as required . Radius all port edges fo r rin g protection. DO NOT RAISE OR LOWER the ports! S tay wi th stock timing. DO NOT ALTER THE INT AK E TIMING! Bol t the exhaus t manifold in place and blend the port to the mani fo ld . TRANSM ISSION HEA D RIN GS Follow t he same steps of deb urring any forging or casting flash and any and all sharp edges. Pay particular attentio n to th e selec to r forks, deburr and radius all the sharp edges of the tangs. Also put a .0 I 5 - .0 20 radius on both ends of the inside diameter of the hole that the selecto r fo r k shaft passes t hro ugh. This w ill give you b u tter smooth sh ifts. On the right hand side, where the gear change drum comes through the case, there is a leve r assemb ly that is like a pair of scissors acting as a detent on t he gear change drum stop pins, this lever assembly is held in place by a hex head bolt . T his bo lt head will sometimes interfere with , the shifting pattern . Remove the bolt and replace it with a screw, Part No . 92011-023. Make sure everything is clean an d we ll greased before asse mbly. CASES AGAIN Ma in b earin gs used are stock; just ma ke sure that th ey are clean. Inst all the right h and main bearing in the R. H. case, p ut the c rank asse mb ly in p osition in th e R.H. case. Now p lace th e ro ta ry valve in its normal posit ion on the crank and layin g flat on the case. Use the rotary valve to scribe the lines you will use to m od ify th e intake port. Dykem can be used to ass ist in lay ou t. Caution : With the solid portion of the rotary valve covering the intake port, scribe a line at the top of the port area extending past the width 0 f the port a t both ends. Rotate the valve. openin g the p ort. That small strip o f metal between the scribe line and the top 0 f the port must n ot be removed; th is is the o n ly su rfac e tha t gu ides th e en ds o f the valve past th e port. Remove th at section and nasty noises along with instant halting ?f JIl0\!vc!, 'p,o!"'C!. ',W QcC,ur'. J1-fte'r,t)le ill, mt jke p ort h as been m odifiea place th e There are no modifications to the head, but do lap th e gasket surfaces of the head and cylinder to achieve a flat surface. Whe n r ead y to bolt on the head, spray both sides of t he gasket with alumin um paint. CLUTCH lhe stock cl utch is not use d . Windy uses the new F·9 Hub Part No . 130S7-o30 and spring plate No. 13 1S7-o05 . These are aluminum and of a new d esign and reall y do the job. You will have to add one more friction plate No. 130SS-021 a nd o ne more expander ring No . 13229-001. I t's half a pound ligh ter th an the steel unit. Fo llow normal assembly procedures using all torq ue valves, etc. Make sure it 's clean and w e11 1ub ed. IGN ITI ON Stock carbs are used on all engines, a 30 mm Mikuni on the 250's and a 32mm on the 350's. Jetting, of course, is di ctated by the event and its location (that's how a tuner is supposed to earn his bread) . Windy says they'll run Castrol-R at 20-1. He sw ears his motors will wail all day long at 9000 r's. Once t he test rides h ad been completed, with Dave and Gary being all pump ed. saying yes to the offer to ride for Kawasaki, AI asked them to ch oose the o th er equipment they preferred, Gary's c hoice fo r a frame was a Trackmaster unit, and, like Dave , the rest was left up to Al and Windy. Just an engine switch is the o rder of business for Gary and he'll use the 350 F9 engi ne for the Friday night IT show and the 250 FS nl motor being installed for the Saturday short track event. Ceriani fo rks were selected to control the front end. The rest of the hardware on Gary's machine is the same as that on Dave's short tracker. That's it folks , the re cipe fo r victory. The people : Al Goslee; Windy Briggs. the mo ney man; Kent Smith, Kawasaki ALDANA'S MOUN~S hardware with a large assist fro m the Da-;e opted to , ~~ ~~t~ D'\l1'\s ~i~ker , • •sP,'icia!ty. , lTJ a.n,u f~,c,t ll ~er~ ;, ;1119 . the.ijwo fram s Jor With Ii.i.s". snorLuacJ<. .mount . . .. m eo- 'n· the mtJoter-9us;'.es9 suits, Dave Aldana a nd Gary Sco tt . ana h is IT m achin e. Dall as says that th e

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