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/125975
The whole 212 pound th ing. Only the head s can be removed with the engine in the bike. Viewing from the rear, you see : clutch housing,lower center; power output shaft, upper right; alternator upper left inside rear cover. With the left case ha lf carried away, everything else sits under the , automotive-type bearing housings. In fact, a car mechanic would ! Honda re-invents t e t I GL-IOOO Service School Sl"ACE II By Lane Campbell "There are two easy jobs on this engine," the man is saying, "Tuning it and doing a valve job." With about 30 Honda Service Technicians (you don 't dare call the m mec hanics any more) and a few other journalists, we're sitting in on a one day high-intensity service 8 school on Honda's flagship GL 1000. As we listen, we realize that the CB 750, that technological starb urst of 1968, is almost old hat now, and even simp le compared t o what's in front of us . The GL 1000 has two wh eels, but from the service department's stan dp oin t, it's an automobile. To remove the engine, one must remove the lower left frame rail and the radiator, then after an ap propriate series of m an eu vers, trun dle the unit out to the left, resting on a transmission jack or so mething with similar heft. The G L 1000 p ow er un it weighs 21 2 pounds, out of the frame. Two Gilmer-type timing belts drive the overhead cams, o ne for each bank. The belts are the same part number as the cam drive belt on the Honda CVCC car. (Now doesn't that give yo u a portent for the future?) The four carbs come off as a unit with their air box, and can be left hanging in the frame when the engine is puIled. Fuel p assages to the individual carbs are cast into the alloy air box. The fuel comes from an automotive-type pump driven off the rear of the right cam. The carbs are co nstan t-velocity Keihi ns which can be -synchronized with standard CB 750 shop equipment in a three-step procedure. It 's simple essentially quicker th an tuning th e 750. Dual ignition points ar e driven o ff th e rear of the left cam and are set by timing mar ks on th e flywheel as seen through a viewing plug in the crankcase. Once the heads are off, any further delving into the engine requires sp litting the cas es, as the water-jac keted cy lin de r bloc ks ar e cast in unit with th e cran kcase-h alves, ca r sty le. This is less hairy than you'd think, provided y ou 've got a proper engine st an d . The front case cover co mes off to reveal the shift linkage, wh ich is dis connected acr oss the case parting line. The water pump (which is driven off the same shaft as the two oil pumps] co m es away with the front cover (wh ich also carries cast-in oil passages to and from the oil filter.) The rear co ver comes off to reveal th e clutch, primary d rive (Hy -Vo chain), and the alternator, which is he avi ly weighted and turns counter to t he crankshaft to help can cel the typical shaft-drive torque reaction. The rear That nine pound alt ern at o r (we ighted to counteract crankshaft inertial comes away w ith the left case half. Dangling chain below alternator is to starter motor, wh ich must come off to get at th ree case bolts, cove r carries aw ay with it the alternator fiel d coils, drive shaft be aring, and kickstarter ratchet. Yes, there 's an " em ergency" kickstarter (ca rried inside the false tank) which connects to t he rear of th e engine, BMW·style. Now for the piece de resistan ce, as it were. With all the peripherals removed, and all the case bolts out, the left case-half comes away with a few taps (carrying oil pumps and alternator with it ), leaving the engine innards inside the right case . The crank rid es inside auto m o tive-st yle bearing blocks with plain bearings, while the transmission sh afts (which are almo st pure CB 750) ride in the normal rolling-element bearings. Inside, the marvels never ceas e. The alternator drive Is a special two-piece gea r, actually two sep ara te gears p ancaked together and held at a few -thousandths inch offset by a rubber-damped cushdrive. This eliminates backlash and gear h owl. The drive unit. Carrier bearing has special seal and retainer n ut , and is especially sensiti ve t o pre-load. There are shock-absorbing devices at both ends of the drive shaft, which rides insi de the right member of the swingarm. The rear drive is basically a car-type hypoid gearset with no differential gears to worry about. Assembly is a matter of careful sh imming and precise pre-lo ading of two sets of bearings to get p roper tooth contact - a whole new trip for your garden-variety cycle wrench. The engine coolant is a water-glycol mix, circulated by a Cen trifugal p ump with a Bakeli te im peller. There 's a plastic coolant recovery tank which sits half-full when the system is co ol. To check coolan t level, yo u look at the tank - don 't remove the radiator cap! If you do , and the system is hot, y ou 11 get the boiling co n ten ts of the reco ve ry tank blown allover you at about 14 psi. The-GL 1000 has an 18 amp-hour