Jerky On / Off throttle

cali_rider said:

ULEWZ said:

Had a terrible stumble going to work yesterday. I climb up 2,000 plus feet to get to work, so when I got off the fwy, twisted the throttle, and bog, bog, then it caught and went. Got the Tech Bulletin M2007-016 ECU done today. Hopefully that will fix the altitude issue I have. Lets see, loosened throttle spring, G2 throttle tube mod, removed slack from cables, PCV with updated smoothness map for the PCV, barbarian mod, now all should be good. :yahoo:

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Mine has done the same at times upon startup.,,,and I am doing all the same things this weekend. However I have the PCIII, not the V. I was looking on where to to find the Wallys smoothness map. Anyone know of a copy? Its seems that the preffered map to start with. Also, anyone know the procedure to install a new map to a PCIII?

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PM me with your email and I can sned you Wally's map and the one Usless pickles did that was his calculated version of Wally's. I've used both when I had a PCIII and they are great.

Well, I added the G2 throttle tube and pulled all the slack out of the throttle.....much better now, like it should have been in the first place....not sure why Yamaha couldnt figure out something as simple as a throttle mechanism at the factory....In all the 20 bikes Ive owned Ive never seen so many F-ups over standards simple crap, like the throttle tube.

cali_rider said:

In all the 20 bikes Ive owned Ive never seen so many F-ups over standards simple crap

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Welcome to the Wonderful World Of Gen II!

(sorry, couldn't help myself )

Not sure that I would keep a bike that I was so unhappy with.

SkooterG said:

Powercommander and Barbarian mod do the same thing. Doing both it just redundant. If the Powercommander didn't cure it then you were not running a good map.

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Well, not quite. The Barbarian Mod and raising the CO will add fuel primarily at idle, with a decreasing effect as the throttle is opened (but it will still be richer)

The Power Commander you can program the individual "Throttle vs. RPM" cells and add fuel just where it is needed, and actually decrease fueling where it is already too rich. And yes, there are areas of the stock FI map whee it is too rich, generally speaking it is with larger throttle openings at lower rpms.

Most of the maps I have ever seen for the PCIII, with an exception being the Wally map, have zeroes in the entire "zero throttle" column (more on the Wally map later). So the CO setting would be adding fuel somewhere that the PCIII map isn't.

The primary root cause for the off throttle to on throttle transition jerkiness is that on trailing throttle conditions the ECU cuts all fuel from the injectors until the rpms drop down to near idle, and then it only adds enough to maintain idle. This is what makes fuel injected bikes have such strong engine braking characteristics as compared to carburetted bikes. Then when you crack the throttle back open it suddenly begins to add fuel at the normal rate and there is suddenly ignition in the cylinder and some power being made... Jerk!

The Wally "smoothness" map does add 10% at zero throttle but only at 1500 rpm. Since nobody actually rides around at 1500 rpm, that cell is essentially useless. Not sure what the reasoning was for him putting a 10 there. Actually, I'm not sure that anything that you enter in the 0 throttle column has any effect in overriding the ECU's fuel cut on trailing throttle programming.

The way that the smoothness map helps at all is by added some fuel in the 2% column to soften the blow, but the Wally map only does this at 1500 - 2500 rpm. Wally must have ridden his FJR considerably differently from me. I don't know about you, but when I come railing into a corner and chop the throttle to reduce entry speed, then roll back on as entering the corner, my rpm is generally in the 2500- 5000 rpm range. So a Wally map should not do a thing for me. And it doesn't, so I don't use it.

The map that I have and use adds fuel all the way down the 2% throttle column from just above idle up to 4500 rpm and in the 5% throttle column up to redline. It gives considerably smoother transitions than the Wally map did. I'd still like to get a custom map for my bike to improve the gas mileage a bit, but this map is the smoothest I have tried.

Here's a link to the map, in case anyone wants to try it or have a look at it. Note: It is is a first Gen map and would probably need some translation to work on a second gen.

I have a 03 gen 1 and put a Power Commander III on it to smooth it out. Wasn't sure it was doing much until I took it out of the line to do a A / B test. What a difference! I couldn't wait to get the PC put back in line. The PC with smoothness map will take all the remaining abruptness out of the throttle and tame this big beasie. I do much of my riding in town, and now it's much easier to control in stop and go traffic. I also find it more controllable coming out of a corner as I roll on the gas. There is a slight penalty in gas mileage, but I'll take it.

I've also popped the center spring on the throttle body to reduce the grip needed on the throttle. With both of these mods, I have a machine that behaves itself.

Steve in Austin

Hey guys and gals,

Any thoughts on a G2 Tamer versus just ordering an '08 or later throttle tube from Yahmie?

Bike Bandit lists the 2008 OEM grip assembly (1211242) for $24.

Concourier said:

Hey guys and gals,

Any thoughts on a G2 Tamer versus just ordering an '08 or later throttle tube from Yahmie?

Bike Bandit lists the 2008 OEM grip assembly (1211242) for $24.

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it's not the tube on the handlebar, that's the same. It's the cam on the throttle bodies. Not available separately.

it's not the tube on the handlebar, that's the same. It's the cam on the throttle bodies. Not available separately.

Oh, I see. Yahmmie "fixed" it by changing the Cam on the TB, rather than at the grip.

Hmmm - sounds like a G2 is in order then...

I've just ordered a G2 to help with this problem but I seem to have come across another problem I am looking for some help with.

I have the Yamaha heated grips fitted and can't seem to get the grip off the original throttle tube as it would seem to be glued on.

I'd welcome any ideas on how to fix this.

Thanks,

Baron.

It's okay folks I've managed to answer my own question. Turns out a 2 hr soak with WD40 has done the trick.

If it comes up again, an alternative to spraying lubricants into the grips is just to use compressed air. This works to refit the grip as well. Just blow air between the grip and throttle tube and it will move without having all the gunk in there.

TomInCA said:

If it comes up again, an alternative to spraying lubricants into the grips is just to use compressed air. This works to refit the grip as well. Just blow air between the grip and throttle tube and it will move without having all the gunk in there.

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Thanks for the tip. I have a compressor so I'll give that a try on reassembly when my G2 arrives.

Well, that's my new G2 now fitted and middle throttle return spring rewound and attached (what a fiddle on that was!) but as yet I haven't had the chance to test the results of my labours. I live up a dirt road and as its either been pissing with rain (muddy) or below freezing (frozen mud) I've not been able to use anything but my car for fear of leaving a trail of broken fairing behing me.......sigh!

At least the throttle action feels good and reliably returns to the closed position.