Stiff throttle modification recommendations

[Shakti]

After putting 15K on my beloved 08 FZ6 I still hate the stiff throttle. At an ever rapidly increasing rate, I experience terrible pain and have resorted to medicating prior to riding. Any suggestions for loosening up the throttle??

Keep in mind I am not a mechanic... I'll probably need to forward this to my mechanic.

 

[ChanceCoats123]

FZ6 uses a throttle cable instead of electrical signals, so make sure the cable is well lubricated. Additionally, there are products you can buy to make the throttle less exhausting on your hand.

 

[TownsendsFJR1300]

After putting 15K on my beloved 08 FZ6 I still hate the stiff throttle. At an ever rapidly increasing rate, I experience terrible pain and have resorted to medicating prior to riding. Any suggestions for loosening up the throttle??

Keep in mind I am not a mechanic... I'll probably need to forward this to my mechanic.

+1^^^^

The throttle shouldn't be difficult at all to turn.

Besides lubricating the cables, check uner the plastic throttle tube for any rust / crap binding up between the bar and and the throttle cable tube. (inside/underneath the throttle grip).

 

[FinalImpact]

Another factor is this;
Its a double pull cable setup. You pull to open the throttle and the other cable pulls it shut with the aid of the return spring on the TB assembly.

• If there is NO FREEPLAY between these two cables, it will twist very hard in both directions. Add play using a set of 10mm wrenches. I'm pretty sure even adding play at the grip area won't fix this one. Go here and if the cable are taunt, add some freeplay to the bottom cable. Loosen the forward nut shove the cable rearward, turn it CCW ~ 1 full turn, put it back and snug the jamb nut. Try that and see what happens. Add more if need be.

IDLE = closed: Notice the curve of slack in the lower cable? Does yours look like this?

WOT = open: Against the stop! You can't see it well, but the TOP RETURN CABLE now has slack in it! Confirm yours has slack in BOTH CONDITIONS!

LUBE:
I use a syringe and tiny telfon catheter to lube cables it slides inside between the cable and the sheth. Vibes from riding, gravity and use will help it migrate down the sheath.

 

[2007Fizzer]

..I still hate the stiff throttle. ...Any suggestions for loosening up the throttle??

I tried heavily lubing both throttle cables. I also tried leaving some extra slack. Didn't work to my satisfaction. I'm old, with relatively weak wrists, especially after several hours on the bike traveling back roads.

I read - on the FJR website - that one solution is to unwrap and cut off one segment of the throttle return spring. The FZ6 has a circular, concentric return spring that has 4 or 5 wraps. If you unwrap and cut off one of those 4 or 5 wraps, it cuts down on the amount of spring tension that you have to pull against - and it should still have plenty of spring tension remaining. I discussed this with one of the mechanics at my Yamaha dealership, and he indicated that this is a popular thing to do on racing dirt bikes. Apparently it allows more throttle control with less resistance. So I'm gonna try it over the winter, while I'm performing other maintenance. Note that YMMV.

 

[TownsendsFJR1300]

I read - on the FJR website - that one solution is to unwrap and cut off one segment of the throttle return spring. The FZ6 has a circular, concentric return spring that has 4 or 5 wraps. If you unwrap and cut off one of those 4 or 5 wraps, it cuts down on the amount of spring tension that you have to pull against - and it should still have plenty of spring tension remaining. I discussed this with one of the mechanics at my Yamaha dealership, and he indicated that this is a popular thing to do on racing dirt bikes. Apparently it allows more throttle control with less resistance. So I'm gonna try it over the winter, while I'm performing other maintenance. Note that YMMV.

I did the throttle un-wind procedure on my old 04. It really never was stiff IMO, but they said it would be better. The spring on the FJR is in the CENTER of the 4 TB's. I did ONE unwind. It certainly loosened up the throttle, the bike "felt faster" however it would barely pull the throttle back.

As for more control, NOT really (IMO). Any bump you might hit, the throttle would move accordingly that much easier.

I left it for about 2 years and put it back. It is reversable, a PIA (on the FJR at least).

The key to releasing or re-tightening is to take a small pastic zip tie and drill a small hole in the very end(pointy end). Bend it into a U shape. Put the hole in the zip tie over the end of the hooked spring. Now you have control how many unwinds you have oncd the spring is off the throttle shaft tab/hook.

The FZ should be considerably easier than the FJR however, I found both the throttle pulls on both bikes, if properly adjusted/lubricated to be about the same.

Now, we did a throttle spring un-wind on a friends 07 FJR years ago and it made a big difference. His bike apparently had an extra wind in the spring, from the factory, (vs my 2004)

I would check adjustments, throttle tube, lube cables, before I would do the un-wind..


Some interesting reading;

Caution with Throttle Spring Unwind Mod - Technical Discussions - FJRForum

 

[SANGER_A2]

The throttle on this bike sucks! I've put brand new throttle cables on mine, cleaned and lubed everything, got the recommended throttle slack and it's still tight. I use a cheapo throttle lock on the motorway to save my hand, but the throttle is still trying to pull itself closed.

 

[TownsendsFJR1300]

The throttle on this bike sucks! I've put brand new throttle cables on mine, cleaned and lubed everything, got the recommended throttle slack and it's still tight. I use a cheapo throttle lock on the motorway to save my hand, but the throttle is still trying to pull itself closed.

If with the cables disconnected at the throttle plate and they work smooth, (no binding, etc) you may try un-winding the return spring one loop.

Its the only thing closing the throttle, that your working against. If its that bad(tight), I would do ONE loop un-wind.

Not being in the center like the FJR, you'll likely have to remove the air box to get to that spring.

Please post if you go this route and the results...