1. A physically challenging job associated with sport-bike servicing or overhaul is the removal and reinstallation (engine R & R) of a multicylinder powerplant. The services of an automotive cherry picker just do not apply, so the work must be done by hand. The rewards of such an undertaking are saving money (about $200 or more), avoiding unaccountable dents and scratches and the opportunity to conveniently upgrade some or all of the contributing cast (exhaust system, carburetion, hoses, oil lines, drive chain, etc.) if you so desire.
2. Start by securing the motorcycle on a rear-wheel stand. An elevated motorcycle workbench will make the initial work easier. It is difficult to juggle a 100-pound-plus engine in one hand while attempting to remove the motor mounts with the other, so it may be wise to enroll the services of a willing helper. Undress the motorcycle to expose the vital components. It may be a good idea to take notes in chronological order, use strips of masking tape to label critical components' location and snap some Polaroids of wire and cable routings, bolt patterns, hose location, ignition settings, the maze under the fuel tank and anything else that you suspect might be difficult to remember. Separate all fasteners in labeled individual containers. Confer with a service manual to see if it contains information you can use; it should provide you with torque settings for the hardware during assembly.
3. Disconnect the battery, starting with the negative (-) terminal. Drain the coolant into a clean pan by removing the lower radiator hose from the water pump. Disconnect the thermal switch and temp sender (located near the radiator cap). Remove the two bolts attaching the radiator cap cluster to the frame. Dislodge the water hoses at the engine and radiator overflow line to the catch tank. Unplug the two-wire electrical connector to the fan. Remove the radiator cap cluster. Note the location and direction of the hose clamps' worm drive. The smaller hose, feeding the heat exchanger, also needs to be disconnected. Have lots of rags or paper towels on hand for any spillage that will occur. Remove the radiator while being careful not to damage it on the steering damper. Inspect all hoses for cracks and replace worn ones.
4. After removing the radiator, start on the exhaust system. First remove the exhaust flange bolts, then the fasteners that attach the exhaust pipe near the rear/bottom of the engine. Loosen and remove the hardware that attaches the muffler to the peg bracket. Standard exhaust systems are usually very heavy, and you might want assistance to avoid excessive scratching. Account for the exhaust gaskets and examine them. Their metallic nature allows them to be reusable. When you have removed the exhaust system, stuff the exhaust ports with paper towels.
5. Drain the oil and remove the oil filter. Replace the drain plug when the oil stops draining. While you wait for the oil to drain, you can disconnect the clutch cable and remove the shifter linkage, countershaft cover and sprocket. It may become necessary to loosen or remove the rear wheel to achieve sufficient drive-chain slack to assist in removing the countershaft sprocket. An air or electric impact wrench will help make the job of removing the countershaft sprocket nut a lot easier. If your drive chain has a clip-type master link, you may consider removing the master link and drive chain to make pushing a motorless bike around a little easier. Besides, it isn't good for the drive chain to sweep the floor.
6. Remove the top motor mounts before you start removing the carbs. Loosen and remove the airbox fasteners and the air filter element and loosen the carb clamps on the airbox side. Pull the airbox away from the carbs and use duct tape or a bungee cord to keep it retracted. If you have a different method of air filtration, such as individual air filters, this part of the job will be a lot easier. Next, loosen the clamps in front of the carbs and pull them out of the intake manifolds. Slide the carbs out via the top starting with the right side. Stuff paper towels into the ports to keep items from dropping in. Loosen and disconnect the throttle and choke cables. On older Suzukis with a single throttle cable, it's easier to disconnect the throttle cable at the throttle housing. Carburetors hold a few ounces of fuel and more than likely some of it will spill out, so be prepared and have rags available to absorb the spilled, smelly stuff.
7. With the carbs removed, there will be a lot more access and visibility for disconnecting the electric starter, alternator, ground wire, signal generator (pick-ups) and the neutral switch wire. The sidestand switch wiring is routed through the countershaft compartment, and it too must be disconnected. Next, loosen the 10mm engine mounts (14mm head) at the bottom in the middle of the engine and remove them, followed by loosening (but not removing) the rest of the engine mounts. Remove the six bolts that hold the subframe to the main frame and the front right engine mount, and remove the subframe.
8. If you have mechanic's gloves at your disposal, this is a good time to use them. Prepare an interim location for the removed engine. Try a slab of plywood or some other nonscratching surface and place it near the work area. Place a small hydraulic or a screw jack under the front of the oil pan utilizing a small piece of wood to protect the oil pan surface. Instruct your helping pair of hands to balance the engine while you extend the jack enough to allow you to take off the already-loosened engine-mounting hardware. Be sure to account for the spacer, located on the bottom (at the right/rear) 12mm-diameter engine mount.
9. Place another slab of wood directly under and to the right of the motorcycle. Plan on setting the engine on this slab temporarily, so that you and your help can gain a better grip of the motor for its next move. The stronger person, or the one with the most experience in this sort of thing, should stand on the right side and place his left hand on the rear/bottom corner and right hand on the front corner of the cylinder head with perhaps a finger or two in the exhaust port. The person on the left side of the bike should get a hold of the shift shaft with his right hand and place his left hand on the left/front corner of the cylinder head. You are now ready to drop (remove) the engine. For best results, lift the engine slightly and move the bottom of it forward so that the horizontal part of the motor moves slightly forward, while the rear of the engine drops down and to the right. Once the motor is dislodged and free of the frame, set it on the wooden slab. The person on the right side must balance the engine solo while the person on the left side of the motorcycle walks around the bike to help lift the engine to its next stop.
10. Secure the engine in a safe location. If it will be exposed to the elements, protect it with a large, heavy-duty plastic bag, after you have plugged and taped all ports and openings with lightly oil-soaked paper towels. Next, clean and inspect the frame and hardware and loosely reassemble all motor mounts and the subframe in the proper order to enhance your memory for the impending reinstallation. This should be the most opportune time to perform front and rear suspension upgrades, tire changes, rear sprocket replacement, detailing, etc. It is also a good time to take notes on what you have accomplished so far to help you remember later.
11. The process of reassembly should theoretically be the reverse of the removal process. After inserting the engine in the bare engine compartment, begin attachment with the rear/bottom (12mm) engine mount bolt. The motor must be set as far as possible to the left so that there is room for the spacer to fit on the right/bottom side between the engine and frame. Install the rear/upper (10mm) engine mount, the bottom (middle) and front/left motor mounts with the help of a jack placed under the front of the oil pan (don't forget to use a block of wood), but do not tighten any of them yet.
12. Reinstall the subframe by starting the four 10mm right-side fasteners and using a round pry bar or a large Phillips (#3) screwdriver to line up the remaining fastener holes. Bolt together the subframe, then the rear/bottom (12mm) motor mount, and then the rest of the motor mounts, and torque them to the specified settings.
13. Reconnect the electric starter, neutral switch wire, alternator, ground wire, signal generator and sidestand switch. Spray the airbox boots and intake manifolds with a light lubricant. With the airbox in place, slide in the carburetors after attaching the throttle and choke cables. Secure all of the clamps and attach the airbox to its brackets. Install an oil filter and check that the drain plug is on and tight. Check that the small hoses to the heat exchanger are in place. Pour three quarts of oil into the crankcase and replace the filler cap. Slide the countershaft sprocket on its shaft and reconnect the drive chain. Apply locking agent before torquing down the countershaft sprocket nut.
Reattach the shifter linkage. Install the exhaust system after placing exhaust gaskets in the ports. Use some grease on the port side of the gaskets to keep them in place while you are mounting the exhaust system. Snug the exhaust flanges in place and then secure the rest of the exhaust system. Come back to the exhaust flanges and secure them all the way. Attach the radiator and reconnect the fan. Replace (put on) the rest of the radiator hoses. Secure the hose clamps and all radiator hardware. Reconnect the thermal sensor, temperature sender and spark-plug wires. Mix a gallon of coolant and pour about three quarts of it into the cooling system very slowly. To bleed the air out of the system, continuously pinch and release the bottom radiator hose. If you have a remote fuel container, hook it up and allow the fuel to fill the carburetor float bowls. Reconnect your charged-up battery and go through a regular starting process. Keep the rpm low until the oil light goes off. Turn off the engine and inspect your work. SR
How and why
For a job of this caliber you should have a pretty full toolbox, and chances are that if you work on your own bike, you do. Specifically, you should have a complement of open and boxed end wrenches, a selection of 3/8- and 1/2-inch drive sockets, extensions, ratchets, a breaker bar, a torque wrench, a selection of screwdrivers and regular diagonal cutters and needle-nose pliers, pry bars, a soft hammer, a couple of drain pans and a service manual. It would be helpful to have a 1/2-inch air or electric impact driver, a Polaroid camera, a note pad, duct tape, hardware containers (coffee cans), mechanics gloves, shop rags and/or paper towels.