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Any thoughts on smoothing out a jerky throttle, especially in first twisting open/closing fully but really across the whole range? Obviously some chop is going to be there but trying to put a sort of checklist to go through and make her as smooth as possible.
I know the following can have a play in throttle chop:
- drivetrain slack
- cush drive
- idle speed
- TPS check/adjust
- throttle cable adjustment
Anything I'm missing? Maybe wheel bearings but those would have to be some bad bearings...
Is this something where a new fuel map can help? I'm completely new to FI.
Last edited by Tekime; 09-17-16 at 10:54 PM.
05GSXR75005SV65090DR350
Wrist calibration?
Its too jerky all the time?
Cliff's Cycles KTM
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RandyO
IBA#9560
A man with a gun is a citizen
A man without a gun is a subject LETS GO BRANDON
hold the throttle more like a screw driver
Tim
LRRS #44
Superbike Services 44
If you are coming off a GS500, then it's likely your throttle application. GSXR is not a smooth touring bike with a mellow engine. It's a razor sharp bike that rewards accuracy.
2021 KTM Duke 890 R
2020 BMW R1250GS Adventure Exclusive
1982 Honda CB750F Super Sport
I found the same thing going from a Goldwing f6b to a VFR1200X.
It is 95% technique and for me it is much, much better after about 700 miles. I am still too conscious of throttle control but with more time it will become more instinctive
get an FI controller. PC or Bazzaz. stock fuel injection mapping is usually terrible at initial throttle application.
LRRS Am #331
Graphic Tailor / Woodcraft / Armour Bodies / Suomy / Cycle Performance Autobody / Shorai / ChickenHawk Racing
My GSX-R 600 is awful in first gear. Not only is the throttle super choppy but the intense engine braking makes it generally unpleasant to ride around in any slow speed (neighborhoods, traffic, etc...) environments. I solved this by just staying starting in second gear. Way smoother
Lube the throttle cable, unless it's ride-by-wire (in which case, change the blinker fluid).
RandyO
IBA#9560
A man with a gun is a citizen
A man without a gun is a subject LETS GO BRANDON
Wow, I did not know that.
Thanks guys I'm delicate like a butterfly on the throttle. It's not terrible, but I don't have much to compare it to. Sharp is desirable, jerky not so much. So mostly just want to form a baseline by going over all the mechanical stuff so I know where I need to improve and not where the bike is just poorly tuned. I'm also learning to feather the clutch a lot in first gear.. making a sharp turn in first and coming off the throttle just a hair too much is a nasty feeling
So nothing else mechanically I should be thinking about?
Also looking to rationalize the purchase of a PC![]()
05GSXR75005SV65090DR350
there are aftermarket progressive throttle tubes
Rev2 Throttle - Motion Pro
RandyO
IBA#9560
A man with a gun is a citizen
A man without a gun is a subject LETS GO BRANDON
G2 throttle tamer http://www.g2ergo.com/store/g2-stree...throttle-tube/
I just put one on my FZ6 and it helped a noticeable amount. I got mine a little cheaper on eBay. At the same time, I removed almost all of the free play in the throttle cable.
My carbed CBR F4 track bike was so much smoother rolling on the throttle than my FZ6. Apparently Yamahas are pretty infamous for it, I remember John at Dyno Solutions said a power commander wouldn't help much.
Last edited by MattR302; 09-19-16 at 01:59 PM.
Is it too sensitive, or does it actually stumble, then jerk? I think most people are addressing sensitivity, but a hesitation could be a problem to remedy.
Having the throttle-cable too tight can have awkward results. Try loosening it just that you get a slight slack-wiggle. But if the bike feels like it's running incorrectly, I wonder if the throttlebodies need to be synced.
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Progressive throttle body is a good thought, will think about that.
Mostly just the sensitivity. I haven't noticed any hesitation per say, but there is a quick drop off when the throttle is right at close. Even when I'm suuuper gentle I have very little control in that last few degrees of rotation. Just looking for ways to a) verify it's mechanically sound & properly set up and b) get a little more control in low gears if possible. Definitely checking over throttle cable adjustment though. The previous owner had some pristine bikes and looked like it was well cared for, but I did discover the clutch cable frayed down to the last thread and replaced it... so obviously not everything was gone over.
I know the bite is inherent to the bike, which is a good thing, but lots of reading on the gixxer forums and many people whining about excessive throttle chop and "TPS sensor fixes" and whatnot. So if I can rule all this stuff out and understand the system enough to check off all the boxes and have confidence in my setup it'll let me determine where I just need to improve.
05GSXR75005SV65090DR350
My R1 is terrible at normal street riding in A or B riding modes. It's almost impossible to ride in those modes on the street due to the jerky off and on nature of those maps. In C mode its much friendlier. I hear lots of talk on the R1 forum of people sending in their ECU to SBK Unlimited or Flashtune they will get A and B modes with more power without the jerky throttle. (NON EPA maps that burn richer than the stock maps I would assume) I noticed that my R1 in A or B mode at higher RPM than you would normally ride on the street behaves much better than typical street RPM's. Maybe those upper rev's don't get the stringent EPA mapping as on and off the gas at those RPM's is rather smooth. Same on the track during track days.
I seem to have had a few bikes in the last couple years with really jerky off and on throttles. Ducati Scrambler was the worst. The R1 is tough on a bumpy street with its on/off throttle. The Aprilia Tuono is a JOY in every mode. Also the Tuono's stock exhaust is freaking loud! Did they pay some EPA Fed's off and get the rubber stamp? Seriously! How did they do it?
Send cash... I need a track day
05GSXR75005SV65090DR350
If they put a pipe on the bike and never updated its map then it will run lean. Does the bike tend to surge a little and hunt when you try to hold it at a steady speed? Does it ever pop or cough when you roll the throttle at mid apex of a corner? That hesitation is usually a sign of a lean running motor. The fix is a Dynojet Power Commander module and a custom map. Often times you can find the maps for you bike to correct a exhaust system. Check under your seats and see if the bike has one installed already.
Check out their page for your bike. It lists a ton of maps Power Commander Motorcycle Fuel Injection Tuning Module
Send cash... I need a track day
Fjr has a notoriously heavy throttle return spring that contributes to Jerky off on throttle transition. You can pop the tank and unwind the return spring one turn. Made a world of difference. Going to see if I can do the same for the r1.
Missed your post. Definitely no PC on the bike. Haven't had any problems with surging and once the power is on it's pretty smooth. I'm also rarely over 8k on the street though. Only thing I've noticed is that at low RPMs it isn't always consistent, every once in a while I roll on around 4-5k and the power isn't there for a moment. Not sure I'd call it a hesitation as it's trying to pull, just not getting the same power and the exhaust has a very different note.
Finally getting comfortable with her but still has a lot of chop, I've found it has a lot less to do with being smooth as it does just being slow. No matter how smooth I bring the throttle open there is a definite limit to how fast I can open it up even that first few degrees.
PC is on the list but I decided to focus on the drivetrain & suspension first while I still have some riding time this season. Chain is in fair condition but going to get a 520 kit and do the sprockets/chain, check wheel bearings/cush drives to completely rule out any unnecessary play and just make sure they are in tip top shape.
05GSXR75005SV65090DR350
Up your idle a hair.
Central Mass Powersports #123
1000rr, zx10r, rmz450, RE classic, r6, S4Rs, xr123, sv650(2), cr250 and a box truck that leaks power steering fluid.
I had a similar issue with the FZ6, before putting a Power Commander, try this cheaper option Throttle Tamer
http://www.g2ergo.com/store/g2-stree...throttle-tube/
Helped a bit