If your bike is not coping with twisted throttle then there must be something wrong either with the clutch plates or with the carburetor.. How? We’d try to elaborate reasons associated with each phenomenon.
A failing/slipping clutch would cause a rapid increase in engine RPM without acceleration and this can be observed very well under heavy throttle, and a lot less under light throttle.
Motorcycle clutch system is composed of friction generating plates which are responsible to engage and disengage engine flywheel from transmission. Clutch slip occurs when friction plates fail to engage properly and as a result, flywheel spins at a different rate than friction plates. Now, lets discuss some possible reasons which may cause clutch slippage in a bike over time.
- Improper Clutch Adjustment
In most of the motorcycles a steel cable is used to engage/disengage clutch from transmission through an actuator arm built into the cover of clutch. If clutch cable is adjusted far tightly, clutch would be held partially engaged allowing clutch to slip.
Similarly, in other type of bikes where hydraulically actuated clutch is used instead of steel cable clutch, this problem can occur if air or liquid penetrates by clutch cylinder supply of brake fluid, which will ultimately reduce the hydraulic pressure responsible to cut off clutch from transmission. So, at this point, fluid must be replaced with fresh brake fluid to regain hydraulic pressure within clutch circuit.
- Weakened Springs
The clutch basket of Motorcycles contain a set of springs used to bring back clutch into its engaged state. The springs can weaken over time and withhold clutch from being disengaged. The springs must be inspected and replaced with a new set if these are no more matching with specifications in motorcycle service manual published by bike manufacturer.
- Damaged Clutch Plates
Clutch plates are weakened overtime because these come with finite service life, just like break components. Racing and other high performance activities can damage clutch plates prematurely, or can provide 40000 to 50000 miles of reliable service if properly cared otherwise. Damaged or thick plates no longer provide the exact friction required to adhere to the engine’s flywheel. Damaged clutch plates or the plates whose thickness are below the minimum thickness requirements listed within motorcycle’s service manual must be replaced.
- Incorrect Oil Type
Wet or oil bathed clutches are the most common type of clutches where clutches are kept in oil to reduce wear or keep them cool. Bad quality oil, for having friction reducing additives, will interfere with the friction plates of clutch and cause the clutch to slip. So, always make sure to use the high quality oil specially directed by motorcycle’s service manual.
Carburetors are mechanical devices which control the ratio of air and fuel entering the engine for combustion. This phenomenon looks very simple but carburetor has many parts, if not set properly, will cause the bike to lose power and run badly, or at worst keep it from starting at all.
So, the correct ratio of fuel and air blending is very essential for engine’s good performance. If carburetor is failing or not adjusted properly it will throw off air-fuel mixture, which ultimately, will result in sluggish acceleration and sufficient reduction in power. So, make sure that your bike’s carburetor is adjusted properly and in good shape if you are observing power loss in riding your bike.