Throttle spring mod

[marcusorelius]

Evey time I rode my Feejer my hand would go numb. So I finally did the spring unwind yeterday. It unsprung so fast I wasn't even sure it did it. Well I rode 170 miles today & what a differance! No more numb hand & t-meister even works better! Even ride'n down the street it feels so smooth & way more controlable. What were they think'n makin it so tight, I had the hand strength of a gorrilla? If'n ya have a sore or numb hand ride'n ya gotta do this!

 

[Crash Cash]

Ohhh yeahhh. That's the single best mod I've done, and it made my FJR Forum membership fee worth it! It's much better tooling around a parking lot now, there's no more clunking and jerking trying to make small precision movements on the throttle.

I also got the G2 cam as well, but I see you have a Gen I, so you probably don't need it.

 

[madmike2]

After all the positive comments from others, the question would be:

[SIZE=12pt]What took you sooooo long?[/SIZE]

Sheesh....noobs! :bleh:

 

[Finn]

Just did mine too and went for a 50 mile hop to check it out. Glad I did. I got this bike last week. Still a noob.

 

[FJRless]

Does the 08 need it, or is it something Yamaha fixed for 08?

 

[Motorad]

Does the 08 need it, or is it something Yamaha fixed for 08?

I now have an 08 and haven't had to release the center spring. I had an 07 and it was brutal before I did the spring unwind (G2 throttle tube, and PC111). I think Yamaha did something to relieve the tension in 08. I do know they changed the throttle pully cam profile in 08. That, coupled with changes to fuel mapping, seems to have fixed the snatchy on/off throttle problem. I would be interested in hearing what other 08 owners have to say. I have always used a wide throttle rocker and my right hand never seems to get tired. I'm not sure what it would be like without it. Have to try it sometime.

 

[Wee Willy]

In my previous life as a control system engineer on a fighter program, I can tell you that we agonized over just these sorts of things: spring rates, camshape/gearing, dead bands, etc. The pilots are after great "handling qualities" and it is pretty much all perception with these folks. There are some fairly good guide lines about what works and won't work, but in the end it's a lot of trial and error in the sim, then maybe additional work in the aircraft during flight test.

Consider an "all-electric" stick for a moment where we can program up just about anything we want. Up & away, the stick is used to command roll and pitch. Its "gearing" is how many roll or pitch thingys (usu. rad/sec of rotational rate at low Mach) get commanded per degree of stick deflection (or pounds of force applied like in an F-16). The gradients (shape of the response per deflection/force) are usually non-linear with dead zones in the center so the pilot doesn't always have to be in the loop. The force per unit deflection of the stick (think spring constant) is one of the biggest items in "perceived" handling qualities. Make it too loose and the pilots really complain that it's hard to control. Overshoots happen a lot and it's hard to track evasive targets well. Fighter pilots like their sticks stiff. Motorcycle riders tend to live at the other end of the spectrum, especially those who have to hold the throttle for long periods.

Bottom line in all this is you are directly experiencing a "perceived" system response to your throttle inputs. Reducing the spring rate on the throttle should give you more sensitivity (as in better ability to control the machine) and a sense of relief over long rides. This mod puts you more in control of the riding things that are important to you, hence its popularity.

Cheers,

W2

 

[RadioHowie]

In my previous life as a control system engineer on a fighter program, I can tell you that we agonized over just these sorts of thing: spring rates, camshape/gearing, dead bands, etc. The pilots are after great "handling qualities" and it is pretty much all perception with these folks. There are some fairly good guide lines about what works and won't work, but in the end it's alot of trial and error in the sim, then in the aircraft during flight test.
Consider an "all-electric" stick for a moment where we can program up just about anything we want. Up & away, the stick is used to command roll and pitch. Its "gearing" is how many roll or pitch thingys (usu. rad/sec of rotational rate at low Mach) get commanded per degree of stick deflection (or pounds of force applied like in an F-16). The gradients (shape of the response per deflection/force) are usually non-linear with dead zones in the center so the pilot doesn't always have to be in the loop. The force per unit deflection of the stick (think spring constant) is one of the biggest items in "perceived" handling qualities. Make it too loose and the pilots really complain that it's hard to control. Overshoots happen a lot and it's hard to track evasive targets well. Fighter pilots like their sticks stiff. Motorcycle riders tend to live at the other end of the spectrum, especially those who have to hold the throttle for long periods.

Bottom line in all this is you are directly experiencing a "perceived" system response to your throttle inputs. Reducing the spring rate on the throttle should give you more sensitivity (as in better ability to control the machine) and a sense of relief over long rides.

Cheers,

W2

:dribble: :dribble:

Wait...WAIT...WAIT!!!

But how does the pie taste???

 

[SouthernCruizer]

Does the 08 need it, or is it something Yamaha fixed for 08?

I now have an 08 and haven't had to release the center spring. I had an 07 and it was brutal before I did the spring unwind (G2 throttle tube, and PC111). I think Yamaha did something to relieve the tension in 08. I do know they changed the throttle pully cam profile in 08. That, coupled with changes to fuel mapping, seems to have fixed the snatchy on/off throttle problem. I would be interested in hearing what other 08 owners have to say. I have always used a wide throttle rocker and my right hand never seems to get tired. I'm not sure what it would be like without it. Have to try it sometime.

***********************************************

I've owned both the '04 and the '08. The '08 is easier on the hands, but I still find it heavy compared to other bikes, for example, my Suzuki GSX650F. I ride every day, so I have gotten used to the effort .It hasnt bothered me enough to do the spring unwind, but I can see how some people, especially those that only ride occasionally and have not acclimated to the throttle tension, would want to do it.

 

[Boostn]

I have a 2008 FJR 1300 ABS, I did go ahead and do the throttle spring mod, made it so much easier. It doesn't pull back to closed throttle right away. But I don't have any problems closing the throttle anyways when I ride. Its pretty unlikely you would just go from WOT throttle at high speed and let it go with your hand completely off. I say, do the mod h34r:

 

[Crash Cash]

My throttle appeared snatchy because I couldn't make small adjustments, I'd keep overshooting my adjustment and kind of "oscillate" around the throttle setting I wanted. After the unwind, I could make smaller inputs without my wrists screaming in pain. It's not as light as my SV-650 twin, and I don't expect it to be, but it's a hell of a lot better than it used to be. Tooling around a parking lot is a LOT better.

 

[Joe Cleland]

I just bought my 2004 used. How can I tell if the previous owner already did this to mine?

Joey

 

[Bigbeavk]

If your throttle hand goes numb. While riding of course!

 

[Joe Cleland]

If your throttle hand goes numb. While riding of course!

oster_stupid: :lol:

I was thinking more of a quantitative measurement. With my gorilla like death grip on the bars I can't tell how springy my throttle spring is.

Joey

 

[n1acguy]

Does the 08 need it, or is it something Yamaha fixed for 08?

I did it on mine. No way do ya need that garage door spring for a throttle return.

Way overkill on the stock spring tension. Could even be less tension than with it unwound a turn and still be more than strong enough to safely return the throttle.

Anyone try releasing it 2 turns?

 

[Richouse]

Could someone post a link to the instructions for this mod in this thread. Might be a good idea for that to be here when someone down the road searches for this mod and this thread pops up for them.

 

[marcusorelius]

The pics in this thread are what I used when do'n it

https://www.fjrforum.com/forum/index.php?sh...c=18322&hl=

 

[Harald]

Anyone try releasing it 2 turns?

I'm not really sure how many turns I released mine. I popped the spring loop off the catch and it whipped around waaaay to fast to count. All I know is that for the last 35,000 miles the spring is positioned where it no longer touches the catch unless I twist the throttle (in other words it provides no tension at all until the throttle is opened a bit). No problems unless you consider slower return to idle a problem - I personally have always moved the throttle in either direction so don't need a return spring at all.