Cycle News - Archive Issues - 1970's

N ith a name like that, how can you call it a Harley-Davidson? arc determined by the course and the rid e rs preference. A stock 18" re ar wheel is u se d by both Beauchamp an d Clark ; Beaucham p uses a 350x 18 T re lleborg knobby, while Cl ark prefers a 400xI8 . Front wheels are 21" Akront rims with 225 Trelleborgs Dean Gol dsmi th rear w heel goodie trick : th e spo ke holes in the rear hub o n the right side are S ia mese (i.e., tw o spoke head s share a common h o le ), w hich le ave s a 10 1 of room for the spokes to mo ve under p ressu re. Dean puts a bolt in the excess space and sec ures it wit h a nut to el imi n ate th e p ro blem o f spokes jump ing abo ut or The bike c o me s with a sproc ke t and a chea te r sproc ket m ade o u t of steel wh ich w o uld se rve very w ell as a boat anc ho r. This is rep lac ed w ith a h ar d anodized a lu m inu n sprocket m ade b y Wh eel Sport of Po rtlan d, Oregon . It' s a 72 ·to oth jobber t ha t , with th e chain , is rna ted [ 0 a I 2·tooth co un tcrsh af't sp ro ck et. Besid e s b ein g tw o and a h alf p ounds ligh ter, th e a lumi num sp rocke t lo o ks a who le h un ch ne at e r. Presto n Pe tty fend ers rep lac e th e stock st eel u n it s and save an ad d it ional tw o p ounds, both fr an t an d re ar. O th er "after mark et" sp ecia lty items are us e d whe re j udged to be su perior o r w here p erson al preference d ictates, such as pegs, han d le bars, th rottle , gri ps, e tc. The engi n e as re ce ived is b asi c ally the Go lde n Win g unit with the tw en tv-two pou nd cast iro n cylinder and five sp eed close ratio gear box as used in the road facers. Dean swears that he d oesn't d o a thing t o the bottom e nds of these engines. He says he j u st bre aks them in gentle for ab o u t two h und red m ile s ou t in the d csert, takes the engine ou t of tb e frame an d goes to work. After removing the head an d cylinder , De an checks the big end clearance wi thout splitting the cases. I f all is as it sho u ld b e , h e gets on to the item s he does chan ge . SUMMA RY Left : stock pist on ; right : H -D Rapido hop-u p ki t pi ston with single Dyk es ri ng. ENGIN E • • • • ~ horsepower, I like Dean Goldsmith 's att itude to wa rd these two areas of performance . When asked wh a t the ma chine we ighed. Dean's answer w as: " It dep e n d s o n whose scales yo u 're using." So instead of te lling me how much it weighed, he sai d that in comparison we ighing, he first weighed a ve ry successful competi tor 's machine and the n, on the same sca les , weighe d Harley Davidson . Ae rmacc hi the Regularity . T he Harle y w as one pound heav ier , and as he pu t it, who cares wh a t th e actual we igh t re ally is. As for t he horsepower th in g, Dean's p h ilosophy is some thing like this : " I don't k n ow ex actly h ow much h orsepower I've got, bu t if I am com pe ting against a thre e horsep owe r law nmower a n d 1 beat th em, the n I've enough h orsep ower. If I'm go t com pe ting ag ainst full -blo wn 25 0 !\lX' ers an d 1 bea t th em, then I've st ill got enough h orsep ower, w hatever it is." .. out. e "n '" N .... Ol C>. I w ould say th at with th e tr ack re c ord o f th e Baja, an d what h as h een accomplishe d to d ate w it h this new proj ect , th at H arl ey Dav id son has co me out ahead no t try in g t o d o it the m selves . Havin g pl a ce d th e ir cu b ic the m o n ey at the di sp osal of flamb oy ant J ack Kri zman , th e y w ill again reap the ultimate success and benefi ts as they have wi th th e Baja. •• 1 J Compare Wh eelsport alumi num sprocket with boat anchor mod el on right , TOP END Thc stock p ist on is d iscarded and rep lace d w ith the single dy kes-rin g piston from the Rap ido S tage 2 Ho p- up K it , part num b er 220 72·68 1\1. As ca n b e seen in th e p hotos , the d iffe re nces ar e in the rings and the fue l fl ow cu to u ts in th e top o f th e ' p isto n . O utside of a .sirnp le clean up . n o other work is d on e to the stock cas t iro n cylin de r. . The h ead is th e alloy type G ol d en Wing unit th at has a flame sq u ish are a tha t e ncompasses about one qu arter at the fro n t of the combus t ion ch ambe r, 1\'0 other changes are m a d e t o th e top end. Caution: Do not c hange, o r in any w ay alte r th e port timing, lea ve it stock! IGNITIO\I This m otor in stock fo nn comes v..i th r a m agn e t o flywheel tha t is b ig en ough and h eavy eno ugh to b e u sed as a flywheel in a lot of cars . It 's in thi s area th a t a lot o f wo rk h as b een d on e and sp e cial manu facturing and ma chin in g ar e n eeded to make th e modifi catio ns . T he e n ti re st o ck ign ition sys te m is remov ed an d di scarded and replaced with m agneto coil an d C O l un it fr om a 400 Suzuki. To us c the Suzuki magneto req uire s the manufacture o f an adaptor plate so th at the stator and rotor assemb ly c an b e mated to the Aermacchi case s. It also requires that a special little too l be manufactured to set th e ignition timi ng. Igni tion timing is set at 2 .25mm b ef o re top dead ce n ter. T his lit tle special to ol is necessary be cause the roto r h as to h e recut to fit th e e n d of th e c ran kshaft an d is not keyed . It is recut for an in terfe rence fit and o nce set in position can n o t be re -adjusted. Outside of the adapto r plate and the special ro to r too l, neither the c ases n or cover have tc be modified in an y wa y . It's really a d amn ne at and basically simple modification, • Check out the elli ptical squish area on the mo d ified head. HOR SEPOWER AND WEIGHT Hooker H eaders built an expan sion ch amber for th is little screame r an d were d yno tes ting it a t the t im e th at 1 w as ove r a t Fil t ro n ge t ting in fo rma t io n for this a rt iele. T he H o oker fo lks had just informed Jac k and De an th at they h ad gotten a three h orsep o w er in crease t he new ex pa ns ion w ith cham ber/sile nce r set-up, h owever, they d idn' t say wheth er it w as useab le horsep ower w ith in the powe r band. O n this su bjec t of w ei gh t an d H eavy duty tria ngulation with added frame pieces, on left . H -D loves its H ooker header. " ..., " c: en ~ w Z W ..J C) >C)

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