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/128239
RPM Kawasaki KKf67 Rick Peterson has been building overbore motors for a long tim e, and after visiting his shop in Covina, California, I walked away im pressed by the company's att ention to detail. His crew not only kn ows what they are doi ng , but they c onduct their business in the most organized manner con - Rick Peterson Motor Sports Dynojet Model 200 (626) 967-3053 40 ,.----,-----,------,--- ii- ,---- --,----,------,-----,--.,----- KX1 67: 38 SAEHorsepowe r KX1~5 : 32.5 S~E Hor5ep~wer , . : - KX167: 19.5 SAE Torque Itt·lbS.): 30 : i : ·········T·········[··········,·········r·······T·····" r" 25 , l" [ i···········1 . , : : - ..__ . _ ~. _ . .... ----_._-.- ". -- i >/.~ .. ·········f··········,··········+·..····· 5 __.. _.. , L ?. 10 --, -------'1'--------- : :] -1 · • ••· : :] [ : . -,-- -I I • 35 ···········[··········r··········[··········;········· ·t ··········[··········j·· i --KX125: 16SAETo rque Itt~lbS.) --,--- ·········;···· , ~ , ~~+ . - ceiv able. Every step of the process from the tim e a customer first calls until the jo b is shipped is docum ented . RPM has better rec ord - k eep ing practi ces than the IRS, and we k now how anal they are. In the case of the KX 167, there are a lot of steps to making the motor "big." After sending in th e ent ire eng in e, in cluding th e ki ck starter , shifter, intake manifold and flywheel, RPM tak es everything apart. Th e first thing they do is remov e the old plat ing from the cylinder with an electro -chem ica l . " proc ess. Then they bore the cylinder to the new 60m m diameter, weld up the old O· ring groove, mach ine the weld off and remachine a new a -ring groove. In the case of the 167, the ski rts at the bottom of the cyli nder become too thin with such a big bore. So they also have m aterial added to them and are then remachined to prevent them from breaking off. Once all of the machining is accompli shed, the cylinder is plated with Nickel-Silic on-Carbide , bett er know as "Nik asil." Th is plat ing is the toughest, most durable plati ng that a bored cylinder can receive. The power valves are machin ed and then reinstalled , then the cylind er head is recha mbered for the octane of the fuel you plan on using. RPM uses Wiseco Pro-Lite pist ons mad e to its own specificatio ns. Its kit also includes new rings , wrist pin and circlips . Then they tackle the bottom end. The cases are split and the bottom end, tra nsmission, cl utch and reeds are inspected . Th e crank is stro ke d by reloc ati ng th e lo wer crankpin hole further from the center of rotation. The length of the rod doesn't change, just the pin location, which means a factory rod kit can be used for rebuilds . The cases are then machined so that there is clearance for the stroked crank . The crank is then balanced and tru ed before the engine is reassembled . The specifi cations on the port s, head volum e, trapped volume and squish are all docu mented and kept on file. Add ition ally , RPM can make suggestions for jetting and gearing. In the case of my KX 167, we fitt ed a Pro Circuit Platinum pipe with a stainl ess shorty silencer and a Moto Tassinari V-Force reed bloc k. Tum around time for a job like the KX 167 takes around two to three weeks and is well worth the wait. An interesting note is that many of the factory teams use RPMfor the plating of their cyli nders, including Mitch Payton and the Pro Circuit team. As a matter of fact, RPM does Bubba Stewart's factory Kawasaki cylin der plating . which is good e,nough for me. O Lw'--'-''-'-'--'-'--'-'-'-'-'-'-'--'-'-.L..L.:..L->--'--'--'-'--'-'---'-'-'--'-'--'-'--'-'-'--'-'-'-'--'-'-.;..L.~'--'-'--'-'--'-'-.L.L'-'.J 2 3 4 5 8 7 6 9 10 11 12 13 14 with t he a d d e d ca pab ili t ies of th e b i k e . T h e f irst th in g t ha t I d id w as send th e sus pe ns io n o ut to Pro Circuit fo r reva lv ing . I also added b illet alu m inum upp er and low er tr i pl e clamps , a rea r d i s c g ua r d , r e a r ca liper g ua rd , c hain guard , a nd c o u n t ersh aft guard f r o m T op a r ra cing . was bea t t o c r a p and wa s a r eal workout fo r both the bike an d m y self. It was pe rfec t for test in g t he m otor on t he fast, silty t rac k (due to the tra ck 's rece nt la c k of wateri ng . due to th e lack of water) . It was also a p er fec t " t est fo r th e rew orked Pro Circu it sus pe nsio n, which I w as ve ry impressed Finally , I add ed Un ive rsal's Sol ex fat h a n dl e b a rs anodized bl a ck , a c o m- w it h . I th o ught t he sto ck bi k e h ad good suspe nsion , but Pro Circu it's se tu p su ited me perfectly , a llow ing t he K X t o g lid e o ver th e ro ugh G H t r ac k . I a lso h ad th e c hance t o r ide o ne o f RPM' s K X 151 s th at d ay , but t here was n o comparison to t he 16 7 . The th in g j ust rips. O v er th e co u rse of t he l a s t few m onth s , I 'v e a lso ri d de n th e b ike nu m e r ou s ti mes at t he so me w ha t superc ro ss y Starwe st trac k a nd t h e new l y r eopen ed C arl sbad U . S . GP tra ck . It's Starw est w he re th e b ik e plete g ripper seat from SDG ( no tu g ging or stapl ing req u ir ed ) , an d G rip z graph ic s f rom Pow ersp ort Grafx fo r the sh ro u ds, and preprinted number plate s as wel l. THIS THING RIPS! O ne thing t h at I made su re I d id in th e months p reced ing t he proj ect w as to make c ertain t hat I spent pl enty of t im e fl ogg ing the stock v ers ion of the b ik e. After finall y ge tting t he proj ect impressed me th e m o st , p artiall y du e to th e fa c t t h at I s pe n d m ore ti me fin ished and then phot o g raphed , I had to suffer throug h watching o ur assis tant o ff- ro a d editor Steve Co x fl og m y "baby" for photos . I f in all y g o t a chance to throw a leg over it lat er in the r e t h a n a nyw here e lse , but a lso b ecau se it s u i te d t he 167 p e rfec t ly N OVE M B ER 5, 2003 ' e y e The cylinder has material added prior to the new a-ring groove be ing machined. The lower cylinder f ins have extra material added prior to being machined. @r;y©O [l[}®W~f} [J)[?@D®©U ® ~ 1] ®CZ; [J)~)[?C£@ [bo@u RPM KX 167 motor including parts and labor $ 1954.00 Pro Circuit platinum pipe and shorty silencer $311.00 Pro Circuit KYB Work s Kit part s and labor, front fork $359.90 Pro Circuit Shock revalve parts and labor $14 9 .95 Moto Tassinari V-Forc e reed block $ 148.00 Topar Racing upper triple cl amp $149.95 Topar Racing lower triple clamp $ 149. 95 Topar Racing billet alum inum caliper guard $3 1.99 Topar Racing billet aluminum rear Shark fin $45 .00 Topar Racing bill et alum inum ignition cover $69.95 Topar Racing billet alum inum countershaft guard $3 1.99 I Powersport Grafx Gripz custom preprinted shroud graphics $99 .95 Powersport Grafx Gripz airbox graphics/ cover $35.95 with its t ight and j um p - ridden nature. I lov e how t he b ik e g ets off th e cor- the day , but the damage was don e th e KX 167's virgi n ity w a s hist ory . Day one of t he b ik e's new lease o n life st arted at G le n He l en Raceway, and w hat bette r locatio n i s t here to put a bike to th e t est. As alwa y s, GH 24 RPM moves the cra nkp in hole to stroke the motor; it rebalances and trues up everything before reinstallation. Powersport Grafx preprinted background s $59 .95 Powersport Grafx preprinted fender graphics front /rear $42.95 n ers n o w , requiring f ar l e s s c l u tc h wo rk. It also a llo ws m e t o ca rr y a ta ll er ge a r through the t ight stuff, an d the throttle response co ming o u t o f t hose t ig ht corners is aw esome. RPM n EO _ S EO SDG U:S.A . Gripper seat Univ ersal Solex handlebars (inclu ding pad) $89.95 Dunlop Tires 756 front and rear Spider grips $99 .99 . $97.98 $15.99