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/125985
me w h er e in th e r c pi u s t h e com b ina tio n of its in cre d ibl y quick corner ing , wi th now e ven harder po we r coming o ut o f the co rners and rare high-speed stab ili ty . Mor e than a few well -tun ed 360 Pursangs are pro ducin g close to 40 HP at the rear whe el and t he weig h t is down to what reaso nable 125s were only th ree y ears ago . It becomes clear th at w it h any kind of ta lent and even slight af fin ity fo r the Bulto family 's n o t ion of a mot ocross machin e, your lap times will go down . But maybe n ot every lap . SO First , you mu st learn to rel at e to th is lad y and there is n oth ing h om ogenized abo ut the 360 Pu rsang. The name its elf says yo u sho uld n't expect th ere to be. The Sp anish m ech an ical response to Am erican consumer "protectio n laws demanding leftside-sh ifti ng m o torcy cle was a clear in dicatio n tha t n o body at th e Bult aco fac tory really tho ugh t a Pu r s an g s ho uld shift on the left. Competiti on man ager Ori ol Puig Bulto had voiced th at op inio n ov er a year ago . T h e A me r ican di s t r i bu t or ha d re tro fitted th e test bi ke with a more s t raig h t f o r w ar d , sana shifter . It impro ved th ings tremend ously but yo u still had to apply yo urself to learn ing ho w to ma ke smo oth, co mplete shifts with th e five-speed bo x. If you didn't rid e it fo r a wh ile. you then had to re-learn. Cons isten t to p t hr e e p lacings in every 500 class fro m No vice to Expert o n th e Pu rsang indicate that such ed ucation is possible with positive tI reinforce ment. Rac ing th e - 360. you will generally have two quite opposite ex perie nces wit h the corners on a mot o cro ss track. You m igh t never get to kno w t he m. even to wond ering if th ere is a better line, because y o u will go in and o u t so q uickly th at th e Pursan g will be do wn at the next co mer wh ile yo u're wondering whethe r to put a foo t d own. It 's like a s uba to mic p article wh ich is neve r anyp lace righ t now ; it was just there . The other ex pe rience enco un tered is t ha t of ins pec ti ng t he q ua li ty, co nsiste ncy, an d to p ograp hy of co mers at ex tre me ly close ran ge. Yo u Can smell the dirt, you ca n feel th e dir t . yo u ca n even hear the dirt: it goes " Bon k" right thr ou gh y our Bell Magnum. The diffe re nces in ap p roach t h at lead to su ch widely differe n t res ults are very hard to p in down . If you d on 't do it "righ t" on an LT R Pursan g, yo u will fall do wn . Wish we c ould tell yo u wha t " right" is on this machin e but the bes t ans we rs, eve n from Experts wi th sing le digit n um bers, we re mainly instinctive and no t very instructive. The one th ing th at was consis ten tly " right" with this m achine was using lots of t hrot tle . Gassing it will never do y o u wr ong. It was also q ui te possible to have both those corn er ing sensations in the same day . The 360 Pu rsan g is a specific so rt of weapon and deman d s full atten tio n whene ver it is in m o t ion. We 'd feel silly going fro m co mplete co n tro l to on th e gro und in a tigh t righthander with no intervening los s of balance; th en we'd see th e same thing h appen to a Na tio na l-le vel Exp ert and the n to o ne of th e top Bultaco r iders in th e state . Yo u must pay at tention to the widely vary i ng r a k e in duced by lo ts o f suspensio n travel at both ends. Yo u must concentrate o n proper wei ght tran sfer wh en cha ngi ng di rections. You must use p rodigious amo un ts o f Bel-R ay pr em ix by t wisting th e th rottle grip toward yo u very h ard. You must stand up going faster than ever b efore d own bu mpy st raights an d let th e machine work under y o u. If y ou can coordinate th ese things. th en y o u will pro ba bly think t hat th e 360 Mk VIII Pursan g is Th e An swe r ... an d y ou will pro bably be righ t. You will win. If it doesn't sound easy. th a t 's be cause it isn' t. This is the same frame, fo r ks. an d eng ine th at Ben gt Aberg used to win th e Motocross des Na tio ns go ing away an d it was not des igned for Tim othy Trailrid er . (However, if you're a very q uick t rail rid er , the Pu rsang makes a really resp on sive woods and bu shes bike withi n the range limitations of a 1.7 5 gallo n tank.) Remedial and p re-race p reparation steps o n the 360 Bul are fa irly straigh tforward but q uite necessary. The Motopl at electronic igni ti on co il b rac ket nuts w ore holes in alterna te inner sides ~ f the f!q, rglass. tank• •~n successive e we ek e n d s , th e s e c on d tim e afte r p a dd i n g w i t h fo am ru b ber . So me brac ket ben di ng and at least ad equate cus h i o n are requ i re d t o preven t embarrassing leak s. The inc reased displacem ent in 19 75 has increased th e effective wrap-around o f t he large transfe r ports. Since, at the time of our test . no rep lacem en t 360 pistons were ava ilable in the U.S .• an alternate p isto n ha d been installe d p rior to o ur rid e. One of th e p isto n ri ng locat ing p in s in th is piston snagged in the de ep er transfer port and little pieces o f a lum in um implanted themselves rando m ly around th e top end. A t rip d own to our frien dly local Bultaco dealer (Skip. aga in.) result ed in both th is d iscovery an d a rebuilt 360 Montader o p iston to slide into the Gary Br a y ove rbo re. Sk ip relocates the p ist on p ins at th e bac k where they do n't come near a po rt, thus el im inating the t empt at i on t o in t erm in gl e w i th de stru ct ive co nse quences. More maint en ance . caut ions : chec k the primary d rive and d on 't be afraid to cha nge the lubricant n ow and then. If the J o resa prima ry chain 100 ks chancey, repl ace it with a Diamo nd . This is not so critical on the 360s since they don't rev as high as the 250 or 125. Make sure the head nu ts are to rq ued co rrectly and always make sure the headstay is tight and intact with the little reinfo rcem en t insets in p lace. A loose or cracked head st ay m ean s des tructive vibratio n. Two cracks in three races revealed that the efficient. quiet pipe is made of relatively thin gauge metal. Rewelding o r replacement with an equally quiet exp ansio n chamber was in order. Pop th e nu mberpl ate sidepanels off the still airbox and see if there are double springs o n each clip to ho ld the Twi n Air foam filt er in place . If there are n 't, p ut the m in. Lack of same cost J. L. Po m er oy a to p five placing at th e Yugoslav 250 GP . Good factories learn by racing - like Bultaco. Pressu re exerted by t his year's "eight inch" Be tors on last year's fo rk sea ls resu lt in so me d rool after a fe w weeks. The Te lesco shock abso rbers should be rebu ilt wi th Bel-Ray LT-I 00 at the first op portu n ity. They are basically quite de cent damper s. Th ings yo u do n 't have to worry abou t incl ude wheels with the ligh test hu b s go i ng o n a pro duct io n 500 mo toc rosser. The small hubs have sprayed-on brake lini ngs an d d o an adeq ua te job o f stopping th e light Pursang whether we t or d ry . Spokes do not see m to loosen in t he smooth pro file Akro nt ri ms. The 36 m m Arna l carbureto r mix es lo ts of premix and air with precision fro m zero to max imum ' R PM. It is a thirsty engine and a 40-minu te moto will leave you wi th a nearl y dry ta nk. The seat is excellent, the pegs are good even in mud, and yo u eith er like the ba rs an d grips or you do n' t , Most detailin g. incl uding rubber covers over th e thro ttle housing and carb is up to to p 1975 m o tocr oss specs. W h en be ing co mpletely candid, Bu l taco develo pment engineers will ad mit th at in bringing a wo rks b ike to the public, as they've d o ne wi th th e 360 Purs i ng, they have pus hed reaso nable devel opment of the Purs an g engi ne and transmissio n to very near its limits. What is re markable is that the 360 has prov en as reli able as it actually is co ns ide ring how lit tle race preparation most sportsma n riders put into their bikes. A gene raIly acc epted rati o fo r G r an d P ri x b ikes is 10 ho urs o f prep a r at i on f or eve ry h ou r of co mpe ti tio n tim e. Usually , many more hours than th at are spen t on each m ach ine. Sin ce th e 3 60 Bul taco is, in esse nce, an uncompro mised works bike (Add Bilst ein gas-o il) shocks and you've go t it.], if yo u spend less time preparing it for a race, you can ex pect less. Whether m ost sp ortsm an riders need o r can even ben efit fro m a true works re plica mo tocr oss bi ke is begging the q uestio n. The rid ers want to buy them and the factories are producing them. You can use up a 360 Bultaco in a few motocrosses if yo u do not attend to it and yo u may never feel completely comfortab le with the LTR suspension and nearly seve n inch es of travel, in part. because you are going at least 10 mph faste r ove r the bumps. But a works mot o cro ss bike is not necessarily built t o l a st m o r e th an a bo ut tw o " -. ..... .. .....~,... . Specificat ions Frame and sus pension Sing le downtube, full crade 41 30 chrome moly bdenum st eel; reinfo rced sw ingarm Whee lbase 56 in. (±. Y, in .) Seat he ight 35 in . Gr o und clearance 9 .5 in. Handlebar w idth 35 in . Fo rks : Betor wltravel 6 .75 in. Rear suspension : Telesco w/165 Ib.lin. spr ings mounted for rear ax le t ravel 6.25 in. Weight ' 209 lbs . wet (No t e: F IM mi nim u m is 206 lb.] Engine/transmission Disp lacement 362cc Bore x stro ke 85mm x 64mm Carburetion 36mm Am al concentr ic (Span ish-built) A ir F iltration Twin Air fo am f ilter in underseat still a ir box accessible by side numberpanels. Ignition Motoplat e lectronic firing two sparking p lugs in synch Primary drive J o resa duplex chain T ransm ission 5-speed close ratio constant mesh ; left or right side 1-N-2-3-4-5 and mu lt i-plate wet clutch Running gear Whee ls/tires Ak ront shoulderless alloy rims ; 3 .00x21 Pirelli MX knobby , front . 4.50x18 Pirell i MX k no bby , rear . Fuel tank 1.7 5 U.S. ga l. capacity ; f iberg lass w/breather tube and dual petcocks. Rec . fue l: Bel-Ray MC-1 @ 50 :1 Fenders frangible f iberglass Kill butto n left -side hand lebar Brakes SLS front and rear (ro d-oper ated in dura lum in hubs Built -in muffler ' Yes , reasonably effective Instru me nta ti o n None Price $ 1645 F.O .B. V irginia Beach, VA . I ,.( of the 360 Bul can do that. There is competrtion hours at a crack no r to very lit tle roo m for co mpro mis e in provide max imum co mfo rt to the rider. I is bu ilt to ,,;;in ., ~ ~ , tv! k - ":IIl versi ,?n ., ' , ~ej 'lg.r,ir.s t ~t. t!, ~ ~~ec~~re ~ flag ." .. .t • ·31