Undoing the Counter Progressive throttle pulley on the 06

After going through the normal motions of trying to smooth out the jerky throttle on the 06, (Barbarian Mod, throttle spring release, throttle body sync etc), I decided to try to undo what Yamaha did to the 06 throttle pulley.

Now let me warn you right off the bat, this has only been tested on one ride, and anytime you introduce something into the throttle assy you run the risk of causing the throttle to stick open, which could have deadly results. Read further at your own risk.

Ok, it really was pretty simple. I took a piece of copper Romax house wiring (I think it is 25 amp) and simple shaped it to fit my needs. I flattened it very slightly with a hammer (softly) and put a hook in one end, and curved the other. It took some trial and error fittings before I got the right length and shape. I had to remove some of the plumbing for the air induction system to get it out of my way to work, no biggie. I used hemostats to position the wire in place and prevent dropping it. I had to also use the NEP throttle lock to pin the throttle open so I could work. Once I got it in place, I pushed it down in the groove of the pulley. I then had to loosen up the throttle cable to make slack in the cable.

I feel pretty certain that the wire can't come loose and jam up the throttle assy in any way, though there is always that possibility. If you see me going by you at 180mph in a 20mph zone, it probably means my mod didn't work and my throttle is stuck wide open (well, you see officer, it's like this....)

Anyway, I took the bike out for a short ride, and it did indeed resolve the issue of the throttle being too sensitive for me. I like the new feel and am pretty happy with the results. For a first effort, I would say I came pretty close to getting it dialed in, though I may have used just a tad too large a diameter wire. I might like to drop it back one notch.

I would strongly caution anyone considering doing this to be certain that they don't create a problem that causes the throttle to bind or stick. I would also strongly recommend being VERY careful not to drop the wire when you are installing, cause it will be almost impossible to get it out of the engine cavity below the throttle bodies without pulling them off the bike. This is why I used hemostats, so I could lock them onto the wire and work it into place.

I put some photos on line of what I did. You can see them here.

https://www.pbase.com/fredharmon/thottlepulley

cool deal, nice pics, and good job. glad it helps, perhaps you can post the changes made to the RPM .vs. 1mm that you measured prior to the mod.

perhaps a large loop of thread or dental floss to the top bend could provide a means to retrieve the wire in the event that the hemostats allow you to drop it. Once the wire is secured, just cut the thread/floss and remove it.

may also consider a SMALL spot bond on the top to make damn sure the wire can't come off -- just an couple of ideas.

So Fred, can you explain a little bit about what this actually did/replaced/corrected, and how it actually makes the change in the throttle operation?

Incredible analysis & work... wish you were a neighbor!

I'm getting better at controlling the on-off switch low speed throttle, but it does require concentration...

DaveT said:

So Fred, can you explain a little bit about what this actually did/replaced/corrected, and how it actually makes the change in the throttle operation?

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Sure. Yamaha changed the throttle pulley in 06. From what I can tell, they basically made the diameter of the pulley progressive, it starts out with a small diameter at idle and gets larger toward wide open. What this does, is make the throttle more sensitive at idle and low rpms, because it takes less cable to effect a large angular change to the throttle plates where the pulley has a small diameter.

The end effect of this is that it makes the bike feel slightly quicker at initial launch and off idle. The down side is it makes it harder to control the engine at lower rpms, and makes the bike feel jerky if you are not extremely careful with your throttle control.

My wire effectively increases the diameter of the pulley, thus making the throttle less sensitive.

I just got back from another ride, and I gotta say, I REALLY like this. It is a keeper, and I am never going back. The bike is much easier to ride and takes less effort and concentration to keep a steady relaxed speed. In the twisties I can actually ride the bike faster than before because I can keep a smoother line.

Remember how when you are going 70 and you twist the throttle and then look down and you are well over 100? Not any more. If you want to go that fast you still can, but you have to twist the throttle more. I think it actually makes the bike safer as you have to want to go fast and you don't unconsciously gain speed when you don't mean to. Overall it just makes the bike more rideable, in my opinion.

By the way, I just went and checked, and the wire I used was 12 guage romax.

Fred - great work. I'll make you a deal though. I have no idea what "hemostats" are, but I do know a little bit about wire (been in the business 32 years). Tell me what a hemostat is, and I'll clarify the wire.

House wire is "Romex" (actually a brand). It is normally a two or three conductor, usually with an additional ground wire. It comes in a variety of sizes that can be bought at any home improvement store. Typical house wiring is either a 14 or 12 gauge (they do make bigger). #12 is bigger than 14. I'm guessing that Fred probably used #12.

What Fred did was take a piece and strip the insulation of one of the conductors. By the way, wire comes in sold or stranded conductor. Stranded means it might have 7 or 19 strands in a smaller wire size that make up one conductor.

You can save money buy trying to find a single conductor wire - either bare or insulated, in the size you need. Usually the insulated single conductor that you might find would be called "THHN" - but be careful because THHN comes in both sold and stranded construction in those sizes.

<<EDIT>> I just looked and see that there is some references to "Romax". I've been away from that part of the business for a while. The Romex is the more traditional term. Sorry Fred.

Hemostats are surgical clamps that are basically really nice needle nose pliers that lock like vice grips when you squeeze them.

Some tool stores carry them as do surgical supply houses.

I used them cause they clamp on the wire and won't release it till you unlock them, which reduced my chances of dropping it in the engine bay (though I still managed to). I use them for all kinds of small maintenance and even carry a set on the bike.

In the 60's and 70's they had other purposes, but we won't go there...

Fred H. said:

In the 60's and 70's they had other purposes, but we won't go there...

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B)

By the way, I rode the bike into work today, and I am definetly convinced that I REALLY like the way it rides now. The throttle is much more controllable and deliberate. It is SO much easier to motor the bike at slower speeds and ride it in a normal relaxed way. This is the way it should have been made from the start.

I am already getting requests from folks wanting me to do this to their bike. I am going to make some extra wires, and will sell them for $399 each if anyone wants one (high cost of copper).

Fred H. said:

By the way, I rode the bike into work today, and I am definetly convinced that I REALLY like the way it rides now. The throttle is much more controllable and deliberate. It is SO much easier to motor the bike at slower speeds and ride it in a normal relaxed way. This is the way it should have been made from the start.
I am already getting requests from folks wanting me to do this to their bike. I am going to make some extra wires, and will sell them for $399 each if anyone wants one (high cost of copper).

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Fred - as I indicated, I work for a large distributor of electrical products. Copper wire is one of our big product lines. As you indicated, copper has gone nuts in pricing the last couple of years. While I think that $399 is probably in line, you might want to pad that a little as copper futures are very unstable right now. If you want, I can give you a quote, but we would probably have a 1,000' minumum. Do you think that would be enough to handle the massive number of orders you might receive?

Lets see, 1000' = 12,000". I figure each bike will take about 4" (that includes some working scrap), so you should be able to do about 3,000 FJRs with that. Let me know if I can hook you up. I can use the business

jjsC6 said:

House wire is "Romex" (actually a brand). It is normally a two or three conductor, usually with an additional ground wire. It comes in a variety of sizes that can be bought at any home improvement store. Typical house wiring is either a 14 or 12 gauge (they do make bigger). #12 is bigger than 14. I'm guessing that Fred probably used #12.
<<EDIT>> I just looked and see that there is some references to "Romax". I've been away from that part of the business for a while. The Romex is the more traditional term. Sorry Fred.

Click to expand...

https://www.faqs.org/faqs/electrical-wiring.../section-5.html

I was reading Romax and it was like listening to a High School Band play your favorite rock music. As an "old school" electrician's helper, Romex is like Kleanex and Jello; a brand name that got permanently associated with the generic term for the product.

'Yamaha changed the throttle pulley in 06. From what I can tell, they basically made the diameter of the pulley progressive, it starts out with a small diameter at idle and gets larger toward wide open. What this does, is make the throttle more sensitive at idle and low rpms, because it takes less cable to effect a large angular change to the throttle plates where the pulley has a small diameter."

Fred

How does this 'mod' affect the 'push' side of the pulley????

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FredHow does this 'mod' affect the 'push' side of the pulley????

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It doesn't. The length of the copper shim is such that it only affects the pull cable.

I rode about 100 miles last night and have been commuting back and forth to work since doing the mod. It has made a world of difference for me, and I have not noticed any ill effects.

In this photo, the throttle is in the wide open position.



Here is a photo with the throttle fully closed with the copper wire shim in place.

Fred,

Do you think something like this is possible for a non-'06? I have long been plagued by an inability to quickly, smoothly & safely pick up the throttle after turning in in the first two gears. There seems to be a fine line between idle and too much. Maybe it's just me? Non-Fred smartass comments not encouraged.... :glare:

Damn.

I said "Not encouraged", but if you must, fire away.

It is very possible this could help the 05 as well if you are having problems with throttle control on it.

The shim effectivly increases the diameter of the pulley. This means that when you twist the throttle, it will not move the throttle plates as much. The end result is that you will have more control and will be able to effect very small changes to power and RPM better.

If you go look at race cars you will see they usually try to give the driver large steering wheels or else they gear down the steering system. It is the same concept. The driver needs to be able to make small corrections at high speeds, and the best way to do this is to make his inputs to the steering wheel effect smaller corrections to the wheels. It also reduces the chances of pilot induced oscillations, or overcorrection. Pretty standard stuff in the man-machine interface and human engineering worlds. If you need more accurate controls, you reduce the amount of change that any given input causes.

So yes, if you are having issues you might want to try this. And there really is not much to loose, as the way the mod is done, you can easily take it out if you don't like it and go back to stock.

Larger grips will provide a similar effect as well, though I am not sure it will be to the same degree.

I have been riding the bike a lot since I did this mod, and I can tell you it is the single best thing I have done to it.

Fred H. said:

It is very possible this could help the 05 as well if you are having problems with throttle control on it.
The shim effectivly increases the diameter of the pulley. This means that when you twist the throttle, it will not move the throttle plates as much. The end result is that you will have more control and will be able to effect very small changes to power and RPM better.

If you go look at race cars you will see they usually try to give the driver large steering wheels or else they gear down the steering system. It is the same concept. The driver needs to be able to make small corrections at high speeds, and the best way to do this is to make his inputs to the steering wheel effect smaller corrections to the wheels. It also reduces the chances of pilot induced oscillations, or overcorrection. Pretty standard stuff in the man-machine interface and human engineering worlds. If you need more accurate controls, you reduce the amount of change that any given input causes.

So yes, if you are having issues you might want to try this. And there really is not much to loose, as the way the mod is done, you can easily take it out if you don't like it and go back to stock.

Larger grips will provide a similar effect as well, though I am not sure it will be to the same degree.

I have been riding the bike a lot since I did this mod, and I can tell you it is the single best thing I have done to it.

Click to expand...

Fred,

Great work! You can count me in as a customer...BUT I am going to stop at your house when I bring my feejer out west from Florida...and YOU can do it. I know what would happen if I did it...I would clamp the thermostat on something and drop the windshield into the engine bay....that would happen before I screwed things up. Keep your reports coming though - I want to make sure you arent dong that 180 mph school zone thing! lol By the way....wouldnt this totally void your warranty??

RR