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Frequently asked Questions Yamaha | Back End

We look at five of the most frequently asked questions for Yamaha dirtbikes

Yamaha dirtbikes – BLUE questions

1. Boot Melter


I have fitted an aftermarket exhaust system on my reverse-head YZ-F which does not have a heat shield on the header pipe. Now every time I go for a ride I melt my boot on the header. What can I do?

I have had this exact same drama on my long-term test bike for the last 12 months. While the DRD exhaust system I have does wonders for performance, I am always left with melted boots. The trick I came up with is to wrap the header pipe in fibreglass exhaust wrapping. Once the header pipe is wrapped it will still get hot but not enough to melt your boot.

2. Exposed Hose


The fuel breather hose on my YZ-F runs from underneath the front of the seat, over the airbox and down into the steering stem. This is where it runs standard but when the rest of the bike looks so neat, I don’t like the look of it. Can I run it somewhere else?

I totally agree. Once the fuel hose is hidden it looks much neater. There is a small gap down the right hand side between the fuel tank and the radiator shroud that you can slide the breather hose down. Push the hose down this gap until it pops out behind the radiator, then you can pop your seat back over the fuel cap and the breather hose will be hidden away.

3. Annoying Grommets


The rubber grommets on my YZ-F that the seat clips into and also the ones on top of the radiator shrouds that the airbox cover clips into get really sticky and are difficult to pop on and off. Sometimes I have to pull on them so hard that I think they are going to break. What can I do?

These grommets get covered in mud and dirt and this makes them a little difficult to pop on and off. Before refitting the seat and airbox cover, give the grommets a spray with silicon. This will lubricate the rubber and allow them to pop on and off much easier.

4. Line Astern


The fuel line that runs down the right hand side subframe rail on my YZ-F is cable tied to a plastic clip that is pressed into the frame. After I removed my tank several times this clip became loose and I’m worried I will catch my leg on the fuel line and tear it off while I am riding. Can I run the fuel hose somewhere else?

Unfortunately there isn’t much room to run the fuel line anywhere else and the hose’s outer covering is stiff so it cannot be re-bent. Instead what you can do is get rid of the plastic clip and cable tie the fuel hose directly to the subframe with a couple of cable ties. This will hold the line tight and allow you to remove it easily if need be.

5. Sagging Feeling


I have a new model YZ-F and I can’t seem to get the sag right. On my previous Yamaha I used to run the sag at 100mm but if I run the same setting on my new YZ-F then I can’t seem to get traction and drive out of corners. I just seem to wheel spin and the back end dances all over the place. Am I doing something wrong?

The new Yamaha YZ-F is a totally different chassis design with little weight in the rear. All of the weight is centered in the middle. For this reason there is no weight over the rear wheel to make the rear suspension squat and get drive when exiting corners. Standard sag measurements do not work on these bikes. Instead, riders find that the optimum sag is between 105mm and even all the way up to 115mm for light riders. The higher you make the rear sit, the harder it will be to find traction and make the rear stable.

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