All 650's Weird issue on my 2019 CB650R

[Mihai Arald]

Hi everyone, I'm new to motorcycles(5 months riding), I got as a first bike, a CB650R 2019. I have an issue where without giving any clutch and holding the acceleration at a fixed point, the bike accelerates like 10% extra(without movement of the throttle), then comes back to my throttle position, like accelerating a little on her own. It does this sporadically(maybe once or twice every 2-3 rides) and a couple of times in a row when it happens. I ride with Traction Control ON. I posted below a you tube link to hear the issue explained previously. It happens between 0:49s and 0:52s.



Do you have any thoughts? Sorry if I posted in the wrong place, I am new here also

 

[FinCB650R]

Some toughts:

1. The trottle on cb650r is very picky close to the on/off stage.
You really need to learn to use it. (helps avoiding the "on/off jerkyness")

2. The throttle handle on cb650r comes with a lot of play (at least mine did, and every other I've tested in the shops 0km driven)
You can do various things to mitigate the play. Adjust throttle cables. Little shim pieces on the bars ends etc.
(If you're to adjust your throttle cables, read or watch some video about it not to do it wrong!)

3. The lack of adjuster on the "throttle return cable" (The one pulls the handle back to 0 position)
You can mod this so you get a adjusting nut on the return cable as well, gives you more options.
(If you're to adjust your throttle cables, read or watch some video about it not to do it wrong!)

4. Pair valve introduces some of the "on/off jerkyness" as well.
I've now removed mine, when I did I noticed the throttle got much smoother on the low revs / coasting area.

Hope any of this helps!
I have posts about the pair valve removal,
throttle cable mods and throttle handle shims in my showroom if you're interested to read about those more. (page 2 and 3)

The Red CB650R 2023

My first "big" bike. The Red CB650R 2023.

650f.bike

Oh, if you're not mechanic-DIY kinda a person, maybe consult the shop you bought the bike from (assuming it was a shop?).

 

[Mihai Arald]

Some toughts:

1. The trottle on cb650r is very picky close to the on/off stage.
You really need to learn to use it. (helps avoiding the "on/off jerkyness")

2. The throttle handle on cb650r comes with a lot of play (at least mine did, and every other I've tested in the shops 0km driven)
You can do various things to mitigate the play. Adjust throttle cables. Little shim pieces on the bars ends etc.
(If you're to adjust your throttle cables, read or watch some video about it not to do it wrong!)

3. The lack of adjuster on the "throttle return cable" (The one pulls the handle back to 0 position)
You can mod this so you get a adjusting nut on the return cable as well, gives you more options.
(If you're to adjust your throttle cables, read or watch some video about it not to do it wrong!)

4. Pair valve introduces some of the "on/off jerkyness" as well.
I've now removed mine, when I did I noticed the throttle got much smoother on the low revs / coasting area.

Hope any of this helps!
I have posts about the pair valve removal,
throttle cable mods and throttle handle shims in my showroom if you're interested to read about those more. (page 2 and 3)

The Red CB650R 2023

My first "big" bike. The Red CB650R 2023.

650f.bike

Oh, if you're not mechanic-DIY kinda a person, maybe consult the shop you bought the bike from (assuming it was a shop?).

Hi, thanks for the reply, i've since noticed it more an more and even got the same feedback from more experienced riders. It happened to me while I was overtaking, in 3rd gear at 6000-8000 rpm. It seems like the engine is coughing or chocking. I am not a mechanic but i like to tinker with stuff in the safe margins of my knowledge.
I bought the bike second-hand from a dealer and even went with it to check for errors and tested compression on it and the fuel pump, but with no result to what is triggering this.
some people told me that, since it has an aftermarket exhaust, the guy before might have done some weird tune or it needs a tune for the exhaust.
Still looking into it, it's driving me crazy, lol.

 

[miweber929]

It’s hard to tell but it sounds to me like you are in a high gear at very low RPM? What gear are you in when that happens in the video? I hear you shift into what sounds like 3rd at maybe 25mph, I think. Is it only when cold or also when the engine is fully warm?

Also from the sound of that exhaust it seems like an open one, probably super short and super loud which is why you are shifting at such a low RPM, to keep the noise town.

If I had to guess from watching the first minute of a video, you have a very open exhaust with no back pressure, the bikes are purposely lean at the 3500-4500 rpm range because that’s emissions testing RPM, and you’re short shifting to keep the noise down. I don’t believe the bike is tuned and those factors are making it hunt for fueling and it lurches. I’m am curious because you’re saying it happens during overtaking at higher RPMs which to me might be clutch slipping.

If you want to keep that pipe I’d get the bike flashed or tuned and that should help. I’d also check your clutch free play.

 

[Mihai Arald]

It’s hard to tell but it sounds to me like you are in a high gear at very low RPM? What gear are you in when that happens in the video? I hear you shift into what sounds like 3rd at maybe 25mph, I think. Is it only when cold or also when the engine is fully warm?

Also from the sound of that exhaust it seems like an open one, probably super short and super loud which is why you are shifting at such a low RPM, to keep the noise town.

If I had to guess from watching the first minute of a video, you have a very open exhaust with no back pressure, the bikes are purposely lean at the 3500-4500 rpm range because that’s emissions testing RPM, and you’re short shifting to keep the noise down. I don’t believe the bike is tuned and those factors are making it hunt for fueling and it lurches. I’m am curious because you’re saying it happens during overtaking at higher RPMs which to me might be clutch slipping.

If you want to keep that pipe I’d get the bike flashed or tuned and that should help. I’d also check your clutch free play.

Hey, thanks for the reply, i bought the bike second hand and it came with a full sc peoject exhaust and in the video, i was running without db killer or cat, since then i installed them bavk and now it is doing that jerk less and only once(not like 3-4 times in a row).When i was coming out of the roumdabout i was switching to 2nd gear.The slipping clutch, i will check tomorrow and come back with updates, should i give it more freeplay, right? And for the tune, i was thinking of a power commander 5, don't have shops in a 150mile radius than can do a tune. Would a PC5 still be fine, considering i will be using a map that matches as close as possible my exhaust setup? Thanks a lot for your reply, it is kinda driving me insane as I love to ride.

 

[miweber929]

Hey, thanks for the reply, i bought the bike second hand and it came with a full sc peoject exhaust and in the video, i was running without db killer or cat, since then i installed them bavk and now it is doing that jerk less and only once(not like 3-4 times in a row).When i was coming out of the roumdabout i was switching to 2nd gear.The slipping clutch, i will check tomorrow and come back with updates, should i give it more freeplay, right? And for the tune, i was thinking of a power commander 5, don't have shops in a 150mile radius than can do a tune. Would a PC5 still be fine, considering i will be using a map that matches as close as possible my exhaust setup? Thanks a lot for your reply, it is kinda driving me insane as I love to ride.

Yeah, just be sure you have some free play in the clutch lever with the bar turned either direction.

PC5 should be just fine.

 

[Mihai Arald]

Coming back with an update, a friend of mine suggested to just unplug the QuickShifter and see if the hiccups are related to bad quickshifter. It appears that this was the culprit for the motorcycle hiccups, which in retrospective does make sense since the hiccups were actually interruptions of spark from the QS reading that I want to change gear even if my foot was planted on the footrest, nowhere near the shifter. My bike is riding like a charm now

 

[Redrocket]

There you go; a bit more useful info for the databank!👍 Glad it's resolved.

 

[miweber929]

Coming back with an update, a friend of mine suggested to just unplug the QuickShifter and see if the hiccups are related to bad quickshifter. It appears that this was the culprit for the motorcycle hiccups, which in retrospective does make sense since the hiccups were actually interruptions of spark from the QS reading that I want to change gear even if my foot was planted on the footrest, nowhere near the shifter. My bike is riding like a charm now

Glad you got it sorted and thanks for the update.