Cycle News - Archive Issues - 2000's

1999 KX144 Big Bore Kit By M A TT F REEM A N P HOT OS BY C A MERO N C OA T N EY e c id ing whether o r not to pur c ha s e a new motorcycle is a d ifficult ca ll, especially if yo u a re only a casua l race r o r wee k e n d wa rr ior. Dro p p in g $4000 -$ 5000 once e very ye a r or so on noth ing more than a stoc k bike is costly and timely. While some can 't fathom the thought of not own in g the lates t a n d gr eat e s t mach ine ry, others ca n 't fa tho m t he thou ght of trying to dial in and bu ild a br and new m otoc ro s s er e ve ry yea r. There a re p retty mu ch two fa ctions wh en it co m e s to m otorcycl e riders: Th o s e wh o want w ha t's new a n d those who wa nt com fort, for as lon g a s c omfort is relia b le. For o ur 19 9 9 KX] 25 , we wanted co mfort, but after m an y d a y s at th e tra ck , reli ability started to fa lter, ou r stoc k engine go t slower a nd o ur litt le g re e n m a ch ine was overdue for a tune up of sorts. In addition to just a tu ne up, we opted to b e e f up our KX] 25 , with m o n e y in m ind. Rick Pet ers on Mot o rs po rt s is bec om ing k nown as t he Vet rider's cho ic e , es pecially with h is ] 67 cc kit for 12 5cc motocros s mach ines. Th e o nly downside to the s ucce ss of th e ] 67 c c kit is that ma ny riders th ink RPM on ly makes ] 67s and a re afr a id to spend th e S ] 50 0 -plus that accompan ie s that partic ula r e ngi ne pa c k age. To a ccommodate the checkbook of th e average Joe, RPM ha s come up with a new ] 4 4cc kit , wh ic h is less than ha lf the cost at $655 (excluding the p ipe ). It's als o a nic e com promise between a sta ndard ne w piston a nd a ne w bike. Th e kit is als o for th e gu ys that do no t necessarily want to send the entire e ngine to RPM, but do want some top- en d work done. RPM te lls its c ustomers to c a II first and go over exactly what th ey'r e look ing for , a nd th ey will build whateve r yo u hav e in mind by changing ev e ry th ing from po rting to fl yw h e e l we ig ht. Rick Peterson himself is also famous for his ana log ie s , so if yo u ask why his company bu ilds big bores whe n he is aw are tha t some people are going to c heat with them , he 'll answer (sim ila r to Cha rlton Hes ton ), "I am on ly loa d ing the gu n a nd cocking the hammer . The custome r ha s to pull the tr igge r." RPM ha s ] 44c c kit s for a ll of th e J apa ne se ] 25cc ma ch ine s , but we felt o ur old a nd tired ] 999 KX] 25 wa s in need of some gru nt. The little KX wa s a lready in need fo r a facelift , s o we figured it to be the best candidate. F or starters , we sen t RPM the entire cy linder with the power valves a nd stock he ad. At th e heart of any RPM cyl ind er is Rick 's own Nikasil , which he is ve ry proud of . Rick testifie s th at he s pe nds a lot of time prop erly cha mfering th e ports and m a king s ure th a t th e p iston -to -wa ll clea ra nce is exact. He fee ls th e results are better than stock. RPM al s o has Fast C ry o g e n ic s t re a t its c yl ind ers for m ax p e rfo r m a nc e , after wh ic h RPM g rin ds the power va lves ba c k to cle a r th e la rge r p iston and re -i n s t a lls th em in th e newl y-Nikasiled cy linde r. Th e c y lin der he ad is cut a nd cc'd to m atch the larger , cu s tom Wiseco p iston . Alon g with a ne w-look ing c ylinder , we go t RPM's re c ommended je tt in g specifi cations, which were very hel pful. For those who are won dering , RPM does not do a ny thing to the engine that takes away from the stock look (spa cer p late, gri ndi ng on th e outside of the cy linde r, etc.), so your secret is s a fe . For test ing pu rposes we ha d th e fo rk a nd s hock re- built by To m Morga n Ra cing (TMR) wh ile th e e ngi ne was in process. We wer e ve ry plea s ed with how the s u s pe ns io n wo rke d as well. We a lso ran a Pro Circu it pipe , wh ich fit the new motor to a T. 26 n D MAY 10. 2000 ' c u e • e e vv s Rick Peterson Motorsports' 144cc kit is the perfect way to spruce up your oldermodel Kawasaki KX125.

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