Cycle News - Archive Issues - 1980's

..... ex> ..... 0') A Moriwaki Engineering chassis and Byron Hines built Suzuki GS1100 engine were used. are Goodyears so the only choice is of size and compounds. A 3.25x18 will be used for the front with a 3.85x18 on the rear. Race strategy calls for soft compounds. and they plan to cbanRe tires. In theory it should be a fairly even trade-off but the difference is that if you don't plan on changing you could get a flat tire which would upset your planning. Also, there's a lot to be said for finishing a race with fresh, high-traction tires. To facilitate wheel changes, the Moriwaki chassis has the neatest and quickest frame stands around. It only takes a couple of seconds to have both wheels off the ground. Byron Hines built the motor himself using information learned from his The Pro-Stock GSII00 Suzuki. crankshaft is basically stock, but the crankpins 4re welded to keep them from twisting. Power is delivered to the modified GSIOOO close-ratio through a highlytransmission modified clutch. Heavy duty damping springs replace the stockers. and the rivets that hold the drive gear to the basket are ex€hanged for larger, stronger ones.. Because the retainer plate behind the clutch will flex under load, small tabs are welded to the gear to keep the plate from moving too far. In the stock clutch, a Bellevue washer is used to give smooth engagement. It is normally found at the bottom of the inner hub. ~med unnecessary in the racebike, it is eliminated by machining the recess iri which it fits and is replaced with a shim. Barnett springs are used. but stock plates are fitted because Barnett hasn't developed the plates yet. With all the modifications that Byron did to the clutch. it works flawlessly. The GSII00 cases are modified in a couple of ways. They were bored out to accept the larger spigots of the oversize sleeves. Heavy duty cylinder studs replace the stockers. A very important modificaiion was to drill passageways in the case to oil the 'transmission shift forks. The standard transmission oils the shift forks throul(h the transmission shafts themselves, but the c1Olle-ratio box doesn't have the same set·up. The cases had to be modified to accept the GSIOOO close-ratio transmission. GS750 oil pump gears replace the GS II 00 gears for 30% more volume. Brcausl' of their proximity to the clutch damper springs, the oil pump gears must be bevelled to clear. VHR uses Wiseco pistons with a 76mm bore for a displacement of 1198cc. Compression ratio is 11: 1 for' now but might have to be reduced. Piston clearance is set at a rather tight .001 inch at the boltom of the skirt. The piston crowns are relieved so that stock head gaskets can be used. The four·valve cylinder head got the usual VHR port job. A VHR valve spring kit closes standard valves which have been swirl polished for improved flow. Camshaft specs have a lift of .345 inch with opening and closing 13°-53°, 53°13° measured at .050 inch lift. Carburetion for now is by 31mm Keihin CRs, but later, some of the new 33mm Mikuni "Smooth-Bores" might be tried. Exhaust is through standard VHR four-into-one collector that has had the tubes heated and moved in for improved /(round clearance. Silting on the bike makes you realize that it is physically small. The weight and dimensions are more in line with a small 550 such as the Yamaha Seca. It seems peculiar to have your knees interfere with your elbows on a 1200cc bike. I rode the Team Hammer bike at Riverside Raceway during a California Superbike School session. After riding the bike for a dozen laps or so, 1 forgot about being cramped; the bike fit my 5'9", 150-pound body like a glove. Only two things bothered me: on braking, my knees wouJd hit the fairing, and the family jewels would get scrunched against the tank; and the bike vibrates. Any motor this large is going to vibrate, but John and Bruce are going to be riding this thing for Ion/( stretches at a time. The motor really pulls at the top end. At 11,000 rpm down the back straightaway. we were doing about 150 mph. But the bike was geared too low. and would be peaked before getting to the flat-out tum nine. In a roll-on comparison with an unrestricted Yamaha TZ750 \ whIch finis-hed I'i,~ht h , in the 1981 Daytona 200. rrstr;t'll'

• Cover