The Jerkiness of Jerky Motorcyle Throttles

[ionbeam]

The G2 tube will help some, and the PCV will smooth out all the lean conditions to eliminate hesitation and stumbling from low rpms...

The G2 will help on the '06 & '07 because they came with a non-concentric throttle pulley. G2 does offer throttle tubes in general for the FJR but I dunno if G2 has a tweaked throttle tube profile specifically for other years or if it is just a quality 1:1 replacement for the stock unit.

 

[GhidorahX]

)....... however, none of that addresses the fuel cut-off that occurs when you roll off throttle to 0%. This occurs below a certain pre-programmed rpm (I think 4500 on an R1, don't know what the FJR is)...... so when you roll off to 0, the fuel injection is cut off, no fuel. When you roll back on, the system must 're-wet' itself, thus the delay.
One tip might be to alter your technique, i.e., downshift to a lower gear into aggressive corners, roll off but roll on a slight bit of throttle as you go into the corner, then the hesitation will be gone as you accelerate out of it. I know one guy who slips the clutch as his technique, but that doesn't somehow appeal to me.

I would get the PCV even with Fuel Moto's regular map, at least it will fix lean conditions that cause stumble at low rpms, particularly from 0 to say 3000 rpm. That in itself is what has made PCIII or PCV users much happier.

@RaYzerman19, et al: Right now I'm not thinking that this relates to the throttle tube, but is a "mapping" issue . . . and the "rolling off to zero" issue, mixed in with bringing the techniques of riding a bike w/ carbs & 6 speed tranny to a 5 speed w/ FI . . . the clash of culture so to speak . . . and the learning curve involved.

But, the problem is also noticed in traffic situations, i.e., erratic drivers in front of me causing me to abruptly roll off; or, as in this recent example, tight canyon road and being pushed faster than smoothness would allow . . . . However, sure, downshifting might offer some solution to keeping the throttle cracked . . . but this road is somewhat of a roller coaster that snakes along rock walls or steep drop off . . . mixed in with bicycle guys who feel they own the road . . . it's one of your more technical roads--and that's what brought this problem out. There are numbers of them around, and I could avoid them . . . but, what's the fun in that.

Looking at the PC-V item . . . there is no free lunch in motorcycling, at least isn't a grand to buy . . . but, not exactly cheap either . . . and then is it "plug n play" or somebody needs a computer program to set it up and fine tune it . . . for whatever cost that might be???

GX

 

[Enn]

Looking at the PC-V item . . . there is no free lunch in motorcycling, at least isn't a grand to buy . . . but, not exactly cheap either . . . and then is it "plug n play" or somebody needs a computer program to set it up and fine tune it . . . for whatever cost that might be???
GX

If you buy it from Fuel Moto, they will set up a kind of map for you that you want, no extra cost for that. Just tell them your wishes and also if you have OEM pipes or not. Then every dealer can install it, many guys do it on their own, they say it is more or less plug & play.

I told them I need to get the throttle smooth and that's exactly what it did. When installing, do not forget to unplug the O2 sensor.

 

[GhidorahX]

Looking at the PC-V item . . . there is no free lunch in motorcycling, at least isn't a grand to buy . . . but, not exactly cheap either . . . and then is it "plug n play" or somebody needs a computer program to set it up and fine tune it . . . for whatever cost that might be???
GX

If you buy it from Fuel Moto, they will set up a kind of map for you that you want, no extra cost for that. Just tell them your wishes and also if you have OEM pipes or not. Then every dealer can install it, many guys do it on their own, they say it is more or less plug & play.

I told them I need to get the throttle smooth and that's exactly what it did. When installing, do not forget to unplug the O2 sensor.

@Enn:

Thanks kindly for the details on it . . . "smooth throttle" is indeed what I would want . . . . Interesting that the O2 sensor is taken out . . . .

GX

 

[Rain Dancer]

"T" Mode on the Gen III, soft and smooth.
Dan

Not to be smart Dan, but if if they had fuel injection tuned properly, (And fly by wire set ups programed correctly) you wouldn't need the power modes. I would much rather do away with those for a linear throttle. Using software just is a band aid...and it sells because folks can ride a bike that has a lot of horsepower and brag about the HP......but always leave it in rain mode. Did you ever miss power modes on your "C10"?

 

[GhidorahX]

"T" Mode on the Gen III, soft and smooth.
Dan

Not to be smart Dan, but if if they had fuel injection tuned properly, (And fly by wire set ups programed correctly) you wouldn't need the power modes. I would much rather do away with those for a linear throttle. Using software just is a band aid...and it sells because folks can ride a bike that has a lot of horsepower and brag about the HP......but always leave it in rain mode. Did you ever miss power modes on your "C10"?

@RD:

Indeed . . . my '86 C-10 is still better sorted in the tight stuff with the on/off transition being very good . . . have to say I'm a bit flabbergasted on the state of mapping/tuning in my '09 . . . . Not having modes available is OK, but just basic rideability or smoothness in the turns is something that the stock system should be able to provide?? And then, if I was a top end power junkie I could pay extra so I could get everything I needed from max power, etc. If it was first year of production I might have to be patient, but it's what ?? 6 years later??? Well, no perfect motorcycle exists for all things . . . first thing I have to get the stock windscreen changed out . . . then, maybe next year I'll look into the PC-V item . . . . In the meanwhile I'll be stuttering my way thru the local canyons . . . . : - 0

GX

 

[GhidorahX]

Following up on the comment, "perhaps you were in too high a gear?" . . . today I did my default canyon run on the FJR, and tried the tight turns in 1st gear rather than 2nd . . . and indeed . . . it was "less jerky" . . . so that might suffice for awhile as I catch up on the new rack and windscreen expenses as the mods for the first 6 - 8 months of ownership . . . trying to keep the modification of everything jones under control . . . .

GX

 

[timk]

Never was an issue for me,I learned not to be ham-fisted with the throttle.

 

[GhidorahX]

Never was an issue for me,I learned not to be ham-fisted with the throttle.

Alrighty . . . interesting comment; but looks like you have a Gen1, which seems to be a bit different than the Gen 2?? But you say "It wasn't an 'issue' . . . because I 'learned' not to be ham-fisted" . . . so which was it? Not an issue, or something that you "learned" to overcome by reducing your ham-fistedness?? : - 0

Either way, I don't think I could qualify for the "ham-fisted" type of throttle jockey . . . pure and simple it's FI mapping that is "lean-fisted" in the on/off transition, meaning you have to "trail" the throttle . . . to avoid the jerkiness, possibly pushing the comfort zone in turns, or drop down to 1st gear to keep the revs up but the speed use-able in tight canyon turns, etc--it's still an "issue" for this bike that will eventually have to be addressed to be acceptable for canyon riding . . . it's a west coast thing . . . .

GX

 

[HotRodZilla]

No it's not. Many of us are perfectly capable of riding the bike without issue. It's not a west coast thing. It's a you thing.

Due to EPA requirements, nearly every FI bike out there has the same complaint. They are all on/off with the throttle. Many fix this by over-richening the mixture at low throttle input. The over-rich fueling mimics smooth throttle input.

Like anything, there is a learning curve, whether there is an issue or not. If you can learn how to operate it, great. If not, maybe you should move on. Your choice.

 

[GhidorahX]

I've never had a problem with my '07...But then again I've always been less of a sniveling whiner and more of a doer.

No it's not. Many of us are perfectly capable of riding the bike without issue. It's not a west coast thing. It's a you thing.
<snip>

Like anything, there is a learning curve, whether there is an issue or not. If you can learn how to operate it, great. If not, maybe you should move on. Your choice.

@Hotrod:

I can see that the COG "mentality" exists over here as well . . . . In terms of my "it's a west coast thing" . . . I was referring to tight canyon roads with steep drop-offs on one side and sheer rock walls on the other, which "timk" may not have the experience of in OH, and so he wouldn't have the problem of being pushed down the road by a freaking Sprinter van, while trying to get the bike to transition smoothly through the tight curves . . . .

I didn't start this thread, and I'm not new to motorcycling, and I'm not a young whippersnapper trying to race through the canyons at top speed. So it isn't "just me" that is having this issue, other people are having it too, and offered their solutions here, including the "lower gear" option, which did seem to help, and I posted about it . . . . And, earlier in this thread you posted "I don't have this problem" . . . so, you don't know what the problem is, for one reason or another . . . .

Whether or not "all FI has this problem" to this degree, might be a matter of "discussion" . . . my 89 Prelude has what is probably a Gen 1 FI system for them, and it has a little "lean" issue, but nothing like this bike, and on a bike it's much more critical to have it worked out . . . . Am I ready to "move on" as you so kindly suggest? Not yet, I'll either "learn not to be 'ham-fisted'" or "I'll get used to it" or I'll do the PC-V mod . . . and then I'll post back about it, here, at that time . . . part of a "discussion" is what forums are about.

Gx

 

[yeravener]

GhidorahX, did you ever get the issue sorted? I have a similar issue on my 15 ES.

 

[GhidorahX]

GhidorahX, did you ever get the issue sorted? I have a similar issue on my 15 ES.

@yeravener:

No, and yes . . . the data that someone posted here on releasing the throttle spring by one "turn"??? looks interesting as a simple option to try to make the throttle less "heavy" . . . but I haven't gotten to the next service interval to try messing with it.

I have seen Rider mag referring to a siimilar problem with other Yamaha models, so I don't think it is "unique" . . . but, I also took the advice here to drop into a lower gear, and that has made somewhat of a difference. Coming from a 6 speed Konk to the 5 speed tranny is something I'm still working on . . . but, lower gear, much lower, has let me trail the throttle through the turns, and, it's "OK." So, what used to be a 3rd gear turn is now 2nd or even 1st; I'm learning to get it into 1st a lot more than I ever did on the Konk. Not a whole lot of cash to throw at the problem, going down the highway the problem doesn't show, only in the tight canyons where I mostly ride. Still, there the carbed Konk is the more comfortable bike to run through the turns, the FJR touchiness on the throttle makes it a little less comfy . . . but, getting used to it, one day at a time, etc,

So, best of luck on it; my mechanic buddy shot the PC-V option down, as a layer of "complication" . . . I will try out this easing the throttle spring option first, and then I might try the, throttle tube aftermarket upgrade, see how that does . . . and then, maybe mess with the PC-V option . . . . First, next step is Rocky Mayer seat . . .

Gx

 

[ionbeam]

The PC-V is an option to consider, it's not another layer of "complication", it should help with the problem without adding any other issues. Since the PC-V offers adjustability you can tune it to your preference. Ideally you would take your FJR to a shop with a DynoJet chassis dynamometer and have a custom map made. You may find that just a Zero Map would help take out throttle abruptness.

 

[Steve in Phx]

This is an interesting thread. I appreciate the constructive feedback.

Just a few weeks ago I followed mcatrophy's instructions to re-shape my throttle tub cam. It did make a difference but not enough for my AE. On a bike with a clutch this would be much less of an issue but when my AE is locked in gear and I'm on and off the throttle at low speeds the abruptness is absurd. I don't have the money for a PCV yet but it sounds like that's the next step for me.

Just a thought... If someone made an aftermarket cam linkage for the throttle body I think this would be ideal. A non-linear pull at the TB would allow greater variability and a lighter pull for the first 1/3 turn of the throttle. This might be a great enough change to negate the need for the PCV.

 

[ionbeam]

As Steve in Phx mentions, the '06 & '07 throttle bodies have a non-concentric throttle cable pulley (not round). This makes the throttle open at a faster rate than the throttle tube on the handlebar rotates making it feel abrupt. Steve cobbled his own fix, you can buy a G2 throttle tube and cam that cancels out the throttle body pulley giving the throttle a linear pull.

 

[Steve in Phx]

Thx ionbeam. I don't think I articulated this correctly but what I'm truly wondering is if we could get rid of the abrupt throttle response off idle if the throttle cable pulley at the throttle body were 1) larger and 2) had a completely different shape. There's only so much you can do with the throttle tube. We could accomplish a lot more at the other end. Hope that makes sense.

 

[GhidorahX]

The PC-V is an option to consider, it's not another layer of "complication", it should help with the problem without adding any other issues. Since the PC-V offers adjustability you can tune it to your preference. Ideally you would take your FJR to a shop with a DynoJet chassis dynamometer and have a custom map made. You may find that just a Zero Map would help take out throttle abruptness.

@ionb:

Personally I haven't ruled out the PC-V, but in my 25+ years of riding I have learned that throwing money at a problem doesn't always "fix" the problem . . . and for the most part does not increase re-sale . . . . At this point the "main" problem that continues is an intermittent stall at low revs after re-starting from gas stops . . . have to keep the R's up for a little while until the "brain" figures out that we are moving. If that problem continues I would consider the PC-V. But, first, the cheaper ideas will be tried . . . .

As Steve in Phx mentions, the '06 & '07 throttle bodies have a non-concentric throttle cable pulley (not round). This makes the throttle open at a faster rate than the throttle tube on the handlebar rotates making it feel abrupt. Steve cobbled his own fix, you can buy a G2 throttle tube and cam that cancels out the throttle body pulley giving the throttle a linear pull.

Somebody here did mention, the throttle tube option, "throttlemeister"??? but, my bike is '09 Gen2 and I have to say that the stock tube has not reduced the twitchiness on the power delivery . . . so I'm not sure if my 09 has a Gen 1 tube and I should try another OEM option, or try the aftermarket tube . . . after the spring tension reduction option . . . . : - )

Gx

 

[mcatrophy]

. . . . At this point the "main" problem that continues is an intermittent stall at low revs after re-starting from gas stops . . . have to keep the R's up for a little while until the "brain" figures out that we are moving. ...Gx

If the stalling is at idle or just as you move off from rest, it could be your idle is too low. General concensus is that you need 1100 rpm.

 

[GhidorahX]

. . . . At this point the "main" problem that continues is an intermittent stall at low revs after re-starting from gas stops . . . have to keep the R's up for a little while until the "brain" figures out that we are moving. ...Gx

If the stalling is at idle or just as you move off from rest, it could be your idle is too low. General concerns is that you need 1100 rpm.

@mcatrophy:

Thanks for the follow-up . . . I'll have to check that, generally I'm thinking that 1000 is where it is set for idle . . . I have a couple thousand miles before the next service . . . but, an easy enough fix if that solves what has been an irritating problem . . . loaded, 2-up . . . low speed stall . . . .

gX