Why is my motorcycle losing power when accelerating?

Question

I ride a Honda Rebel 250 motorcycle and over the past few days I find that the bike is losing power when accelerating fast.

When I twist the throttle to accelerate quickly (in any gear) I hear the engine sound increasing in pitch by a lot more than I'm used to hearing, but the motorcycle doesn't seem to respond and performance is very poor. If I then twist it back to a position of slow acceleration, the engine noise returns to I'm used to hearing (still the accelerating noise but a lot lower pitch) and the performance also seems to be appropriate to that level of acceleration.

What could be wrong with the motorcycle?

Answer 1

My knowledge of motorcycles is limited so I could be wrong, but it sounds like the clutch is slipping.

Answer 2

I realize this question has been answered, but keep in mind that any carbureted engine can bog down under throttle and cause a lack of acceleration.

If it can be backed off and regain acceleration, then I'd suggest carb tuning. If the engine revs, but no acceleration then it's a slipping clutch.

Answer 3

There are two cases to be considered here both the carb and the clutch could be culprits here. Let me explain.

If the engine warm and is at the normal operating temp and you floor it and no acceleration that means the culprit could be clutch.

If the engine is not warm enough and it has only been about 5-10 minutes then it is the carb, there is a specific term to explain this phenomenon. In this case you floor the throttle and poor response and if you go easy on the throttle and you get the corresponding acceleration.

Before you confirm it is the clutch ride it for about good 30 minutes and then roll the throttle like mad and see which case it falls under.

but don't forget to check the adjustment to the clutch make the cable little tighter and see if it makes any difference, this is a simple thing to do and hurts nothing, you can revert it back real easy.