i just got my new yfz and after five rides the battery was dead. I took out the battery and opened it up and discovered it was bone dry. I filled it and charged it, and when i went to start it, it made a clicking noise and started smoking. I checked it and it holds a 12.5 charge but when i tried to start it it droped to 6 volts and was not enough to start the quad. This is really pissing me off, it breaks after 5 rides. Also one of the tabs on the bottom of the plastic tank cover broke off on the first ride. now the other tabs are starting to break. I really hope that the dealership covers the problem!

 

Yep, kinda sounds like your haven some trouble with your battery huh?[img]i/expressions/face-icon-small-wink.gif[/img]

 

same thing happend to my buddy tokk a little longer though take it to the dealer they should replace it

 

enFORCER, I like your 'tude!


yfzmxer99, the yzf's battery needs a battery tender. They are made small and light for weight savings. That is just one of the inconveniences of owning a pure race quad. Perhaps you would be happier with a 400Z? ... just jerk'n your chain... of course I know that nobody would be happier with a Z.

 

lol

anyway.... some yfz have a defect with the battery...think overcharing or something idk n idc
go to dealership n get it fixed under warrenty or put a cbr battery in it htats wut a lot of racers do (need to weld a lil bit)
or just get a new 1 (still on stock one, waiting to find cbr bat)

 

Copy and paste from one of schwendi's past posts comlements of Doug Gust:

Quote

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Q: I have heard of battery problems with the YFZ450's where it overcharges the battery and then runs poorly. Have you guys heard of this problem and any ways to fix It? And also was it just some of the first ones from Yamaha or is it just a general problem?

Thanks
Mike


A: We're glad you asked this question. There is a lot of confusion about this issue, so we'll give you the straight scoop.

With the help of Jeff at M&M Cycle in Kalamazoo, MI, we have pieced-together the facts.

First of all, there is nothing wrong with the quad or its electrical system. However, it does require special maintenance procedures and riding practices (as does any race machine)

There are two main issues which lead to the YFZ battery problem:

1) The battery itself: The battery is a Dry-cell, sealed battery. Unlike regular batteries, its internal voltage is about 13.5V (as compared to about 12.6V for standard batteries.)

Due to the higher voltage, you need to use a special charger for it. Regular battery chargers will only charge it to about 12.5V max. This is only about 70% of this battery's capacity.

Several companies make the higher voltage chargers, but the recommended one is made by Yamaha. It's called the Opti-mate 3, and is available from any Yamaha parts dealer for about $60.

2) The YFZ is a race quad, pure and simple. However, when trail-riders get ahold of this quad, problems with the battery can occur if they don't follow some procedures Here's why: To maximize Horsepower, the charging system on the YFZ was designed for racing. High RPMs (racing conditions) are required to properly charge the electrical system. The quad was designed this way because electrical charging robs HP. For racers, there is no problem (reported), but for trail riders there may be. When you're out trail riding, high RPMs are usually not the norm. Plus, the electric cooling fan is often in use due to the low speeds. This fan runs right off the battery. The combination of the fan and low RPMs results in the battery draining while you ride, and this can result in ignition problems.

So, what can be done about it? Here are some key things to do with the YFZ:

A) It is important that the battery is fully charged to its maximum 13.5V prior to being installed in the YFZ for the first time. If it was not fully charged before installation, that battery may not accept a full charge (ever) due to the battery 'memory'.

B) Never use a standard battery charger. Only use a Yamaha Opti-mate 3 (or equivalent)

C) Only use the Resistor-type Spark Plugs from the factory.

D) When trail riding, if the fan is coming on all the time, turn ON the headlights. By turning on the headlights, the charging system activates and will allow the electrical to keep up with the load of the fan without draining the battery.

E) After trail rides, top-off the battery with the Opti-mate 3 charger. (It comes with a quick-connect plug so it's easy to use frequently)

So, is this a design flaw by Yamaha? No. This quad was design by and for racers and racing conditions. It's the slow, trail-riding conditions which can result in electrical drainage. I wouldn't have though that turning ON the headlights would help with battery drainage, but it does. Yamaha doesn't want to harm the Horsepower by increasing the charging system output, and I hope they don't (for racer's sake). But, maybe in the future, they will offer to sell some sort of 'electrical boost kit' for the slow trail riders to install.

Personally, I commend Yamaha on the overall design of the YFZ450, inside and out. If we've got to turn on the lights to keep the juice up during trail rides, so be it.

 

If you go the the Yamaha website, they have some info on problems with the batteries. I can't recall exactly, but I think it came down to cold cranking amps, which was why the battery wouldn't last.

 

The battery on YFZ failed and was replaced. Now i always ride with the lights on and have not had another prob at all.

 

I'm calling bullcrap on this one. These guys are obviously good with motors, but don't have a clue about electricity. The charging system on any vehicle "turns on" when the voltage in the battery drops enough for it to need to. It doesn't activate or not activate based upon having even more of a load on. If the fan is running the battery down, the charging system should turn on.

What this really means (and what I've heard elsewhere) is the charging system is over charging and putting more load on helps by keeping the voltage down. Overcharging will definitely cook the battery, much like you saw. What probably wrong with the design (yes, it's wrong), is they made it under charge at low rpm to minimize the over charging at higher rpm. That's a sign of a poor regulator. The reason mx'er have less problems probably has to do with the amount of run time for each time they start it. Every time you use the starter, there's an increased demand on the charging system keeping the voltage down for a time.

Also, 1 horsepower = 745 watts of electrical power. Keeping up with the spark plug and fan is nowhere near that much power. Sounds like a lame excuse to me to claim they didn't want it charging completely. It's really no different than the Banshees (at least my cousins older one) with yellow lights at idle.

 

My battery died at the begining of the season. So, I went out and got an Interstate Battery. Shortly ater that I took my head lights off... I haven't had any problems since. Starts everytime.

Lt84