CB650F Throttle response

[John brookes]

Can anyone help. I have a 2017 cb650f. When I pull away from a start the throttle response is really poor. First there is a flat spot, then it will surge forward so then I have to close the throttle. When you change gears if you haven't got plenty of revs on when you release the clutch you get the flat spot again. Has anyone else experienced a similar thing. If so what's the cure ?

 

[miweber929]

Nope, throttle response is great on mine after I adjusted the throttle cable play, have you done that? From the factory there is a lot of freeplay.

Has it always done this or is it something new?

Are you the original owner?

Any mods?

 

[John brookes]

Yes I had the bike from new. I told the Honda dealer about the throttle. They said that sounds normal,. Told me to use more revs. I've had 12 motorcycles all over 600cc and l have never experienced this before

 

[Jerry]

With a cold engine the throttle response is a bit off on my bike as well, but once the engine gets up to temperature it gets a lot better.

 

[ADIOS600]

I have a 2015 cb its as sweet as a nut. In fact it will pull away without virtually any throttle. It snatches the very odd time when slowing in 2nd gear but that maybe once every 4th ride. Your bike doesn't sound right to me. As Jerry said when hot it should be a lot better. In fact I find when cold the bike can actually be a bit frisky certainly no flat spots. Have you got many miles on the clock.

 

[Kayman29]

Blame the pair valve added to north american models. Doesn't happen on Thai bikes because there is no pair valve. Read the forums. Do the modification for under $100 and enjoy
smoother rides.

 

[Jerry]

Doesn't happen on Thai bikes because there is no pair valve

Really? European market models have the pair valve as well and I guess Australian ones do as well. Since all 650F's are manufactured in Thailand, I find it somewhat hard to believe that they'd go to the lengths of creating what's basically a separate set of SKU's for just a single (and relatively small) domestic market.

 

[Brammers]

All our bike have PAIR, even the TH model. It's needed for emissions regs on the cat converter.

TH and CA model are identical in 14-16 models and all models are pretty identical 17+ due to Euro4 standards.

 

[Kayman29]

I would beg to differ as none of my two Thai CB650F rattle like a bucket of bolts like my Canadian version. No emission requirements in Thailand like UK or Canada. I will have to wait until I get back to Chiang Mai to do a personal inspection. I could be wrong but why then are some models so bloody noisey and others don't make a peep like that damn pair valve?

 

[Jerry]

I can't say for sure, but I don't feel like my bike makes a lot of noise either.
When I start the bike and let it run idle I do hear a faint ticking, a bit like the hourwork of a clock, coming from under the tank. From the descriptions of the sound I've read hear, I assume that must be the pair valve. It's so subtle I would never describe it as "bloody noisey".

 

[Road Hog]

Well .to me it could be 2 things ,first in cold weather i have this problem before warming up and secondly
i have this problem only after putting in 95 gasohol, if it is 95 benzine i have no flat spots.In thailand alot of the
fuels are very dirty but i never have trouble with 95 benzine car or bikes.

 

[bishop]

Cold weather, could be oil pressure relief valve opening and closing. I had this noise on my Ninja 250R with thick oil and Canadian winter. It went away once it warmed up. I have not used my CBR650F in cold weather yet.

Regarding throttle response, my silencer was missing from my two bros full exhaust. I installed it, and seems to be a lot better. It could also be in my head.

 

[Kaspariigais]

I have question about my Honda CB650F throttle valve handle bar. Everyone know that there need to be free play for 2-3mm movement when you are acelerating, but what about side movement from left to right??? Does it have to be tight, loose or small movement?? My honda throttle valve handle bar have prety big movment, about 3mm and for me it's distracting.. How about you?? is it normal???

I know that there need to be a some loose movement, but isn't that too much?? I was at our local dealer, and they said that it's normal, and that Honda factory special designed so..also they couldn't answer me how big movement is normal?? In Latvia we have shitly local dealer, they know everything and nothing..

I'm interested in how is on your Honda? is it tight, loose or small movement??

Also do yours handlebar wights is moving around when it screw is tighten up?? because for my honda on left side it not moving (it's tight), but on the right side it's moving on around ?? (this question is crap, becouse it don't change anything)

Everything is original.. Honda CB 650F ABS , 2018.

Thanks..

 

[miweber929]

Free play from side to side is normal and some bikes have more than others. It’s not really an “adjustable” thing like free play is so you’re kinda stuck with how much all of your parts tolerances come out to be.

Both of my Triumphs are fairly tight, with minimal side to side movement and Honda’s lately, especially the Thailand built ones, have a bit more excessive movement. It kind of is what it is and I get used to it when I swap back and forth.

It’s probably not a great answer, but it’s normal.

As far as the turning bar end that’s another one that’s seemingly hitting a lot of 2017’s and 2018’s because a number of people have mentioned it recently. Looking at a parts fiche you’ll see the bar end actually mounts to a heavy, metal slug that is suspended in rubber and held from sliding out by two clips. So as an assembly it’s designed to “float” but the bar end itself should be tight to the slug. You should be able to turn it if you really try but it shouldn’t pull out and should have resistance as it spins.

Once you determine what’s moving you’ll know if it’s normal or not.

 

[Road Hog]

Kaspariigais,Just to let you know my cbr650f 2014 is tight with side to side movement.

 

[Jerry]

Oh, I was just thinking how my '16 model has a small amount of side-by-side free play as well (I'd say 3mm is about right). Nothing that ever worried me though.

 

[rustyeyed]

I had some sort of issue like this but there were a few things I noticed:

1. Engine cold
2. PAIR valves
3. Throttle play

I had many mods done, so during that took the PAIR valves out and put the bike on the dyno and it's like a point and shoot weapon now !

 

[Kingsleh]

Oh, I was just thinking how my '16 model has a small amount of side-by-side free play as well (I'd say 3mm is about right). Nothing that ever worried me though.

Same here with just about the same amount of freeplay. Also a '16

 

[DC5tig]

Can anyone help. I have a 2017 cb650f. When I pull away from a start the throttle response is really poor. First there is a flat spot, then it will surge forward so then I have to close the throttle. When you change gears if you haven't got plenty of revs on when you release the clutch you get the flat spot again. Has anyone else experienced a similar thing. If so what's the cure ?

Only just got my 650 doing the same thing

 

[ghehen]

Only just got my 650 doing the same thing

let's the bike warm up for 2', engine rev low down to 1k3-1k6 rpm. What's call "Close loop" controlled by ECM to prevent engine damage at cold start could be the reason.