Jerkiness

[ScottyUSN]

Glad to hear you found your solution. :drinks:

 

[fastpappy]

I go in to buy a suit. I find one that I like. I try it on. OK not bad, take in a little in the seat, let out a little in the waist, shorten the sleeves and the pants a touch. Ah! Perfect. Same principal with the Feej. Just my $.02.

Oh come on, fastpappy. "Take in a little in the seat" is the equivalent of adjusting the tire pressure or shock rebound, NOT spending $400 on a PC III or V.

Shortening the sleeves ain't exactly the same as dropping seven large on a Russell saddle.

I bet you smooth-talk the ladies real good, too.

The Feej has so many low cost or no cost adjustments that can be be made I haven't spent any serious farkle bucks as yet except to upgrade the sadedles and my GPS. I really think a lot has to do with living with the bike and getting used to what it takes to get her to do what you want the way you want. Yea kinda like the ladies.

fastpappy

What kind of adjustments are you talking about I test rode an 07 FJR and an 09 connie back to back today and as much as I disliked the connie and liked the FJR the connie was the one I was must comfortable with as far as the throttle control went .

Throttle Spring Mod and Grip Puppies (increased diameter) both seem to improve throttle control. Adjusting cable play and idle should also help and as I said training that right hand is a big part.

 

[tercol58]

I plan to test ride an 08 this weekend hope it handles better

 

[fastpappy]

I plan to test ride an 08 this weekend hope it handles better

The Feej is one of the best handling machines out there it's just a matter of getting used to the old girl.

 

[RinconVTR]

Having had worked on a new to me 07 for the "jerky" throttle, I'll enter my two cents after the "FEEL" that I solved the problem.

I have a PC3, and I did not feel much difference switching maps around until:

1. Tightened the throttle cable to the point there is next to zero play.

2. Unwound the throttle return spring and lubed the heck out of the entire throttle control system. Greasing the tube, oiling the cables, even lightly spraying all the return springs on each throttle body with Tri-Flow. Movement is slick and smooth as hell now.

3. I did not mess with the accelerator pump (yet) because I think the bike is very smooth now. But it seems we could reduce (and increase if desired!) the throttle response via this PC3 feature. This would be my next step, and last a G2 if I still have an issue.

In screwing around, I formed some opinions to the root cause.

1. This being my third FI bike, I'm used to abrupt FI throttles, so I dont feel the instant response is the root cause but it compounds the real problem. (The G2 would definitely help those who cant or dont want to get used to this.)

2. I feel the root cause is driveline lash (and felt by many riders due to abrupt response FI). This was a big problem with older shaft drive bikes too. I think Yamaha simply doesn’t hold extreme tolerances to help reduce costs. But lash is always more in a shaft vs chain or belt drive system, when all else is equal.

 

[Fred W]

2. I feel the root cause is driveline lash (and felt by many riders due to abrupt response FI). This was a big problem with older shaft drive bikes too. I think Yamaha simply doesn’t hold extreme tolerances to help reduce costs. But lash is always more in a shaft vs chain or belt drive system, when all else is equal.

Hmmm... interesting thought.

Is it drive line lash really larger on a shaftie? I mean if you take the rear wheel in hand and move it when the bike is on the center stand, does it move more total degrees on a shaft drive vs. a properly adjusted chain drive? It will certainly be consistent (regardless of suspension articulation) whereas a chain drive will not be.

Or is it that the limits of the lash are extremely abrupt on a shaft drive because almost all of of the lash is (intentionally) between the ring and pinion gears, whereas a chain has accumulated tiny amounts of lash in the looseness of the chain, and so hitting the lash limits will feel softer?

I know my Fuel injected VFR is pretty jerky in the off to on throttle transition, and it has a chain. My assumption was that the jerkiness was due to there being almost no fuel delivered during closed throttle / trailing throttle conditions, then suddenly lighting a fire in there when the throttle is cracked open.

 

[ionbeam]

Lash 1

Lash 2

Chain lash

 

[RinconVTR]

2. I feel the root cause is driveline lash (and felt by many riders due to abrupt response FI). This was a big problem with older shaft drive bikes too. I think Yamaha simply doesn’t hold extreme tolerances to help reduce costs. But lash is always more in a shaft vs chain or belt drive system, when all else is equal.

My assumption was that the jerkiness was due to there being almost no fuel delivered during closed throttle / trailing throttle conditions, then suddenly lighting a fire in there when the throttle is cracked open.

From my own experience, I have notice far more lash on shaft drive bikes vs chain. But not all. I've ridden some chain driven Triumphs (ST and Speed Triple) that had so much lash, it made some of my Hondas feel like a Swiss watch. So I wouldn’t say my opinion is across the board true, but I would say "typically".

On the fuel cut off theory, I read A LOT about this when I nearly bought an FZ1. They have a fancy fix for $200 that adds fuel during the normal cut off period, and the feedback is all over the place. IMO, adding fuel during decel is wasteful on an FI bike, reduces engine braking, and doesn’t fairly solve the issue. If at all, some question.

A lot of this is also personal preference and perception. Making nothing 100% regarding this topic.

 

[Fred W]

On the fuel cut off theory, I read A LOT about this when I nearly bought an FZ1. They have a fancy fix for $200 that adds fuel during the normal cut off period, and the feedback is all over the place. IMO, adding fuel during decel is wasteful on an FI bike, reduces engine braking, and doesn’t fairly solve the issue. If at all, some question.

And yet, that is essentially what the PCIII does to soften the blow.

 

[ionbeam]

Note the fuel profile during period H and the fuel compensation indicated by 6

Straight from the FSM:

The reason it feels abrupt and rude is because it is abrupt and rude. While it gets an EPA atta boy, in real world driving it sucks.

 

[RinconVTR]

On the fuel cut off theory, I read A LOT about this when I nearly bought an FZ1. They have a fancy fix for $200 that adds fuel during the normal cut off period, and the feedback is all over the place. IMO, adding fuel during decel is wasteful on an FI bike, reduces engine braking, and doesn’t fairly solve the issue. If at all, some question.

And yet, that is essentially what the PCIII does to soften the blow.

Why do you say that???

1. No map I have tried to date made any pronounced difference with on/off throttle transitions. The "smoothness" map does smooth the motor a little, but not during on/off IMO. Some others say it made a world of difference.

2. I have never seen changes at 0% throttle numbers from the stock setting of ZERO.

3. Arent most claiming 08+ bikes mapped better (yet still have fuel cut off on decel) and do not have abrubt throttles? This would mask some driveline lash, and/or that too may have been improved, but IMO it proves that adding fuel at 0% throttle isnt the fix.

 

[Fred W]

2. I have never seen changes at 0% throttle numbers from the stock setting of ZERO.

You haven't seen my map then. There are a number of other custom maps that have fuel added in the 1st column, usually from ~2000 - rpm on up. Even the Wally Smoothness map adds a +10 in the first column, but only at 1500 rpm for some reason. I didn't find the wally map to work very well for me.

Putting positive numbers in the first throttle column at RPM rows above idle speeds will result in softer off-on throttle transitions.

The zero throttle column is readily available for just that purpose. The fact that the supplied DynoJet maps have all zeroes in the first column doesn't mean that it has to remain that way.

Fattening up the next first few columns (2% and 5%) will also help smooth things out in the transition as the power hit will not be so abrupt. That is where the DynoJet and wally smoothness maps concentrate primarily.

I don't have and haven't ridden an 08 or later FJR so cannot comment on how "fixed" they are. Some people do not feel any abruptness or lean surging on an '05. I could not live with mine, and so programmed it away with the PCIII.

 

[RinconVTR]

All maps I found on the web, including the smoothness map "06fjr_calculatedSmoothness.djm" and the others from the same site have ZERO in the 0% throttle. I'm looking at them all right now...trying to find one that adds fuel at 0%. I see nutt'n.

EDIT TO ADD PIC OF SMOOTHNESS MAP:

 

[Fred W]

I have no 2nd gen maps.

The map I am running was a custom one generated on a dyno by Ryan Schnitz tuning for one of the other forum members. I subsequently made some tweaks to further improve the off-on throttle transition.

I can send you the file, but it would not apply to your 2nd gen.

 

[Fred W]

Here's a look at what I'm running:

This was based on dyno results from a similar bike. Only difference is that I do not have a staintune.