Cycle News - Archive Issues - 1980's

ernor spring. Each spring has a different rate and is color coded and wh en installed fool the governor into th inking that th e motor is turning at a higher or low er rpm than it actually is. This makes the exha ust valv es open eithe r earlie r or later th an normal, giving th e engine eithe r sna p p ier o r m ore mell ow power. In stall in g th e sp rings is fairl y sim ple and can be do ne at the track or alo ng the tra il with j ust a few tool s. It wo uld be a cinch to cha nge the go vernor spring if there was quick access to it, but unfortunately you have to rem ove th e ent ire rig ht side cover. This cou ld be simp le eno ug h, too, but to remov e the case th e exhaust p ipe, kicksta rter and brake lever have to be rem oved first. These are all easi ly removed in a few minutes th ough. Once th e case is off th e go vern or spri ng ca n be changed by remo ving therocker arm pin. If you' ve never disassembled a Honda before, locatin g the pin for the first time can be' con fusing wit hout a detai led shop manua l. We've included a ph ot o to guide first-timers right to it, though. The spring is easily slipped right in, th e case reassembled and yo u' re ready to go after about 20 minutes. When yo u hit th e tra ck or trai l with the alte red sp ri ngs, the power difference is noticable right awa y. T he softest sp ring makes the exhaust valves open much sooner th an th e stock 6400 rpm, giv ing th e Honda explosive po wer right off th e bottom fo r when there is excelle nt tracti on. Switchi ng to th e stiffest sp ri ng for slick sur faces giv es a power hit th at co mes on very graduall y as th e engine rpm rises. . The other two springs open the valves slightly earlier than stock and improve the power d elivery, altho ugh the change is much more subtle than th e springs at th e two extremes. While dialing in the power is simple and can be done at the track , a lter ing the suspension for even better performance than stock often requires the work of a q ualified mechanic. And the re's no one better Springing for low-cost CR250 improvements By Nate Rauba The 1989 H onda CR250 is p retty much raceready right out of the crate, except for the little adjustments that make a bike suit a particular rider. T h ere is plenty of good, usable power for th e average rider and the suspension 'd ' II h work s .we w en set to n ~r preference and track conditions. While the Pro class rider may want even more power than the stock engine deliv ers, the average owner will probably find the stock pow erband more than adeq uate and just wish to dial it in to his particular . type of riding. The first thing that usually com es to mind is a pipe to broaden the powerband, but there are other methods. Moose Racing has come up with a different approach which alters the time when the Honda Pow er Port ex ha ust va l v~s open, and we go.t a h.old of th eir Power Valve Tumng Kit to see how it works. We also wanted to improve th e stock suspension, so we sent th e forks and rear shock to Suspension by Jak e. headed by former fa ctory Showa mechanic Jake Thompson. for some fine tuning. The Honda Power Port exha ust valves raise the exhaust port as the engine rpm rises and ar e actuated by a governor mechanism that works against a spring. Moose Racing's Power Valve Tuning Kit cons ists of four springs whi ch can be used to repl ace the stock power valve gov- (Above left) Not only does Jake Thompson of' Suspension by Jake handle fork and shockmodifications for Hondas, but he also does other brands as well. (Right) Moose Racing's kit includes four springs to help tune the power ef the CR2SO. (Below) This pin must be removed in order to change the governor spring, which is located beneath tile power valve actuating arm (upper right). qualified to perform Honda suspension service than Jake Thompson. Thompson was with Showa's racing service for seven years before he left to start hi s own company. Suspension by Jake. and he has set up suspension for motocross greats such as Rick Johnson . David Bailey and Bob H annah. Thompson will change th e val ving to suit your particu lar riding needs. so we had him dial in our forks and shock. With j ust a few changes to both co mpression and rebound val vin g at both ends he had o ur suspensio n working bett er than ever. T he forks and shock were sudden ly much more responsive to smaller bumps. and working in harmon y. Riding th e bike felt like one of those . slow-mo tio n replays of a rider bla sting over a whooped straight, where both ends just seem to gently rock back and forth. The gentler action makes it feel like even though. the bik e is being bounced aro und it is still moving forward instead of just go ing up and down. Although Thompson 's specialty is the Showa suspension found on Hondas, Suspension by Jake also has the sam e modifications available for Kawasaki , Suzuki and Yamaha suspension components. He also does shock oil changes for all models. . The Moose Ra cing Power Valve Tuning Kit or the Suspension by Jake shock modifications are two relatively inexpen sive ways to improve Honda's potent CR250. Moose Ra cing's kit sells for only $29.95, while both shoc k and fork modifi cations will run a ro u n d $250.00. Rear shock revalves cost $ 150.67 and the fork overhaul will run $70.00 without parts. Thompson says that most newer forks often don 't need new bushings, seals, etc.• but that older forks may need these parts which can run up to about $40.00. depending on what needs to be replaced. Where to get' it: Moose Racing, 6235 S. Santa Fe Dr., Littleton, CO 80120 800 IMOOSE-IT and Suspension by jake, 2909 Oregon Ct. Ste. C-3, T orrance, CA 90503 2131 533-8122. •

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