QuestionI own a 93 Kawasaki Ninja zx-11 C4. I have had the bike 2 years and when I first for it I could ride just fine but sometimes when I was going in second, especially up hill, the bike would slip into neutral. About a year ago I was riding hard and hit second wrond and now the bike will not go into second at all and I have to shift straight to third. I can get it in second if I hold the shifter up but it just jerks for a while and slips out the second I let off the shifter. People tell me its a shift fork broken. Is this true? Also an unrelated or related problem is in first when I accelerate it is jerky with the jerks coming at about 2500, 4500, and 6500 RPMs. When I got my tires changed last the mechanic said my crush drive was cracked. Its just styrofoam though so I dont see how that would cause the jerkyness. Any input and advice would be greatly appreciated. Thank you for your time.
AnswerHi Neil,
Review the below pasted tech file.
Respectfully,
Mark Shively
Motorcycle Transmission Problems
By Mark Shively
Slipping out of Gear:
Trying to mate slower spinning sliding gears with very high spinning fixed gears is hard on the transmission. If the transmission is slipping out of gears, the gear's dogs and cogs are rounded (worn) and must be replaced.
Race Shifting:
Shifting gears at or near redline pre-load the shift lever with your toe (raise the lever). When you want to shift quickly twist the throttle closed and then full-throttle again. Don't use the clutch. The transmission will shift into the next gear. This is a racing technique known as "pre-loading the shifter.” It should shift as quickly as you can turn the throttle. It's not the best thing for the clutch and transmission, but racing MC's get complete rebuilds frequently.
Inside the Engine:
When you step on the shift lever, the shift linkage turns the shift drum slightly and causes shifting forks to move. Shifting forks mate with shift drum via dowels and grooves. The shift forks move sliding gears to engage the gear's dogs with its mating gear's cogs.
When a gear is “forced” to engage another gear, as if trying to shift from Neutral to the next gear, expensive damages may result. This causes premature transmission and clutch parts wear and failure.
Hauling in Neutral:
Tie-down straps secure our motorcycles and ATV’s well when used properly during transportation. We tend to use a variety of materials and things to secure motorcycles and ATV’s when transporting.
When the motorcycle/ATV is not properly secured, it may move during transport. If the transmission is placed in gear, shift forks flex under the load and weight of the motorcycle as it moves. Same goes with the clutch and drive chain. These parts are easily damaged. Place the transmission into Neutral and properly secure motorcycle with quality tie-down straps.
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Gear Shifting Faulty:
Doesn't go into gear, shift pedal doesn't return:
Clutch not disengaging
Shift fork bent or seized
Gear stuck on the shaft
Gear position lever binding
Shift return spring weak or broken
Shift return spring pin loose
Shift mechanism arm spring broken
Shift mechanism arm broken
Shift pawl broken
Jumps out of gear:
Shift fork worn
Gear groove worn
Gear dogs and/or dog holes worn
Shift drum groove worn
Gear positioning lever spring weak or broken
Shift fork pin worn
Drive shaft, output shaft, and/or gear splines worn
Over-shifts:
Gear positioning lever spring weak or broken
Shift mechanism arm spring broken
