Acceleration and Deceleration Jolt / Harshness

[Mickey Dublin_imp]

Hi friends, long time no see.

The issue I am having is this - In almost every gear, though it is worst in 2 through 5, If I twist the throttle from 0%, I will feel a rough, jolt through the drivetrain. This happens if I'm twisting on or off even slightly fast. To avoid it, I have to apply power or come off it extremely slowly. It feels like the engine is putting down power immediately, but there is something along the line that "catches up." It kind of feels like how I would expect a very loose chain to feel, but I just did a chain adjustment with no real change.

I do have a decent amount of slack in my throttle cable compared to my other bikes. Could this be the issue? If so - is there a way to adjust that on these bikes.

Thanks in advance for any help. I tried searching but could not find anything similar.

[the Ferret]

In my experience FI equipped motorcycles respond best to easy on and off throttle responses. Yanking or chopping the throttle will result in jerky response from the bike.

[Whoops]

Hi friends, long time no see.

The issue I am having is this - In almost every gear, though it is worst in 2 through 5, If I twist the throttle from 0%, I will feel a rough, jolt through the drivetrain. This happens if I'm twisting on or off even slightly fast. To avoid it, I have to apply power or come off it extremely slowly. It feels like the engine is putting down power immediately, but there is something along the line that "catches up." It kind of feels like how I would expect a very loose chain to feel, but I just did a chain adjustment with no real change.

I do have a decent amount of slack in my throttle cable compared to my other bikes. Could this be the issue? If so - is there a way to adjust that on these bikes.

Thanks in advance for any help. I tried searching but could not find anything similar.

Have you checked your chain for excessive slack?

[pekingduck]

Excessive cable slack will definitely make the throttle feel jerky, and the bike hard to ride smoothly. I like to have a tiny bit more than 1/8" slack at the circumference of the flange part of the grip, but the manual says up to 1/4".

It's the upper cable on the throttle, and you just need to slide the rubber boot away from the adjuster and nut, loosen the lock nut, and turn the adjuster out. Before you tighten everything up, let the bike idle and turn the steering slowly from left to right, making sure there is still freeplay in the throttle.

[PowerDubs_imp]

How many miles on the bike? Has the back wheel ever been off? Maybe the cush drive is worn.

How are the sprocket teeth? Especially the front?

I actually had a friend ride down the street one day...then I saw him stop...and behave weirdly. I walked down the street to him...and long story short..his front sprocket was completely rounded off- NO teeth left...and the chain was just spinning.

[Mickey Dublin_imp]

In my experience FI equipped motorcycles respond best to easy on and off throttle responses. Yanking or chopping the throttle will result in jerky response from the bike.

Thank you, Ferret. I do try to be gentle, but this is far more jerky than any other FI bike I've ridden.

Excessive cable slack will definitely make the throttle feel jerky, and the bike hard to ride smoothly. I like to have a tiny bit more than 1/8" slack at the circumference of the flange part of the grip, but the manual says up to 1/4".

It's the upper cable on the throttle, and you just need to slide the rubber boot away from the adjuster and nut, loosen the lock nut, and turn the adjuster out. Before you tighten everything up, let the bike idle and turn the steering slowly from left to right, making sure there is still freeplay in the throttle.

I will try this next. If it makes a difference I will post an update in case future folks have a similar issue. Thank you.

as mentioned, adjust your chain 1st.

Sorry for the confusion - Chain has already been adjusted.

How many miles on the bike? Has the back wheel ever been off? Maybe the cush drive is worn.

How are the sprocket teeth? Especially the front?

I actually had a friend ride down the street one day...then I saw him stop...and behave weirdly. I walked down the street to him...and long story short..his front sprocket was completely rounded off- NO teeth left...and the chain was just spinning.

These are great points - Bike has only 5k miles, so I don't suspect the cush drive to be worn, but the rear tire was changed by previous owner. It is possible they did not reinstall it. I will check on those sprocket teeth, but with the mileage, I do not suspect that as the issue.

[mvk24_imp]

+1 for too much slack in the chain.

When you adjust it make sure you're rear wheel is straight.

Luckily the tensioners on both sides have markings so make sure they're in the same place on both sides. A little goes a long way in those adjustments chain slack wise.

You also mentioned slack in the throttle cable so might as well adjust that while you're at it.

My kz440 had a bit of a jerk from a stop and its because my cush drive in the rear wheel was pretty shot and I didnt notcie it much with the belt drive but when I converted to a chain it was much more noticeable.

2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca

[Mickey Dublin_imp]

UPDATE: Adjusting throttle cable slack fixed the issue. The amount of slack was pretty far out of spec.

For those replying about the chain: I adjusted the chain before making this post and it made little to no difference. The chain was very close to spec.

[mvk24_imp]

UPDATE: Adjusting throttle cable slack fixed the issue. The amount of slack was pretty far out of spec.

For those replying about the chain: I adjusted the chain before making this post and it made little to no difference. The chain was very close to spec.

Awesome happy to hear you sorted it out!

Hopefully this well help someone in the future trying to diagnose the same problem.

2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca

[the Ferret]

Good deal.