ATV won't start

[ac777]

Well my yamaha atv is sitting on the Ice right now and doesn't want to start. Used it to pull my house out and it ran fine then, now it turns over fine, but won't fire. It did this to me earlier this year, and I had to bring it in the shop and warm it up, but now it is out on the ice, I need to get it going, Any tips or suggestions? Thanks

AC

[ac777]

Thought I would add that it is a 95 yamaha 350 big bear, and normally fires up like a champ.

[Roofer]

Maybe bad gas. Try some heet in the gas tank.

[piker007]

Check the battery. It might seem like its turning the motor over fast enough but its not. If you have a pull start try that.

[ac777]

Well, the big bear is back in action, I did both of the above. I added some heet and even tried a little ether, and she still wouldn't fire off so I jumped it with my truck and she fired right up.

Thanks for the tips

[Dave S]

Be careful using a vehicle to jump an ATV. Your looking at the equivolent of using a 6 lb maul as a fly swatter.

In other words, you could really toast your electronics in the ATV by using a truck to jump start it.

[Sandmannd]

I've heard that Lep. You could also try to bring the battery inside to warm it up before starting. But it looks like you got it going this time.

[fivebucks]

When my ATV gets cold I find it starts better to manually pull start it a time or two to get things moving. Then the electric starter works better for me.

[piker007]

Glad to hear shes runnin again.

[Chode2235]

I put a can of ether right in my gear box when going out in the winter. I have a 700 sportsman twin, and she is a cold beast.

A little ether goes a long way.

[BobT]

Be careful using a vehicle to jump an ATV. Your looking at the equivolent of using a 6 lb maul as a fly swatter.

In other words, you could really toast your electronics in the ATV by using a truck to jump start it.

I'm not sure I completely agree. Someone with more knowledge can correct me if I'm wrong.

An automobile charging system will output between 13vdc and 14vdc. I believe the ATV should be about the same. In either case, the battery is a 12vdc battery just like a car battery, only smaller with lower capacity. Once a battery has acheived its full capacity, it won't take any "extra." What it can do is heat up and begin to boil off electrolyte but that would take some time. To momentarily use a car to jump start the ATV I do not believe should be a problem. But, just like any battery (car, boat, ATV) you don't want to leave a 14v charge across the terminals of a 12v battery for an excessive period of time as this will damage the battery.

Bob

[Dave S]

Bob,

thanks for your post. I'm am in no way a battery expert, but what has me concerned is the CCA (Cold Cranking Amps) of an automobile battery versus an ATV battery. There's a huge difference in the size of motor that battery is trying to crank over.

[BobT]

I understand where you're coming from but it might be a bit off the mark. The current that a battery can deliver is not what it will deliver. The car battery can be rated for 10,000 CCA but if the starter motor only requires 200amps, that's all it will TAKE. Take is the optimum word.

The car's battery or charging system will not force the ATV starter to use more power than it demands. That demand is a function of the starter motor's internal resistance. You also get a few other factors involved with a motor such as inductance and capacitance but in the end, the starter motor can only draw the amount of current it needs up to a fixed maximum based on these factors.

Imaging the potential power supplying our homes. If what you are suggesting was true then I should be tripping my home's 200A main breaker all the time because there is far more than 200A potential supplying that breaker. My appliances each only use what they need and no more.

Bob

edit: CCA is a rating of what the battery is capable of doing, not what it will do under all circumstances. If the device being supplied doesn't need all of the available power, the battery won't get it's feelings hurt.

[Phred52]

BobT, Well said, You might also add that, using an automotive type battery (with greater CCA's) gives the operator the opportunity to crank the engine over longer than the starter is designed for, thus potentially shortening the starters life. If you look in your owners manuals it'll state the engine should be turned over for x number of seconds and then you should wait for x seconds/ minutes before attempting to start again. You will find this precaution in nearly every owners manual of every electric start engine, including your cars and trucks. Phred52

[Roofer]

Hook the ends to a car battery while it is running and put the other end on your tongue. Do the same with an ATV. Let me know which one puts out more power. Will it be the same?

Volts or watts mean squat. It's the amps you have to worry about.

[Macgyver55]

You are exactly right Bob. The battery doesn't "push" amps into the starter....it "pulls out" what it needs to start. Thats why you can run one, two, and three batteries in parallel for trolling motors and such without any problem.

[Roofer]

The starter yes, but the current is being put to the battery.

Here is a question on another forum.

If I hooked two 12VDC deep cycle batteries together in parallel, one having a higher voltage, would there voltage equalize?

Answer

Theoretically, the higher voltage battery would discharge in the lower voltage battery until both voltages are equal.

Practically, if the voltage difference between the two batteries is high then the a high current will flow, the batteries will get hot and may explode. In this way, you degrade the battery's life because you overheat it.

What is more, if they dont have exactly yhe same thermal characteristics then there will be a small voltage difference between them and a current will flow and discharging one in each other. Also, if they dont have exactly the same internal resistance the battery with the higher internal resistance will discharge less and thus having a greater voltage than the other battery , thus a current will flow between them when you disconnect the load.

It is better you connect their negative poles together and put a diode on each positive pole with its anode connected on the pole. Then connect the diodes' anode together and you have paralleled batteries which cant exchange charge between them and cause problems.

__________________

[Roofer]

If the car or truck is not running, it will be OK.

[Dave S]

Bob and Mac,

Thanks for the clarification.

[BobT]

Hook the ends to a car battery while it is running and put the other end on your tongue. Do the same with an ATV. Let me know which one puts out more power. Will it be the same?

Volts or watts mean squat. It's the amps you have to worry about.

YES, it will be the same! Both provide 12vdc supply, all things equal your tongue has the same resistance, you'll experience the same current flow (amperage), watts will be the same. By the way, please don't try this. It would be a really, really stupid thing to do.

Volts are a measure of electric potetntial difference between two electrodes. (12vdc)

Ohms (resistance) is a measure of resistance.

Amps (amperage) is a measure of current flow.

Watts is a measure of the power output. In a simple DC circuit it can be calculated by multiplying volts x amps.

Amperage is caused by the voltage potential overcoming a resistance. A short-circuit is an example of near zero resistance. In this situation, amps are very high. We're talking nearly infinite. This condition can cause serious damage to a battery or other power supply. An open circuit (battery not connected) is an example of near infinite resistance. In this situation, amperage is extremely low.

When a voltage is applied to a resistance, current will begin to flow. If the resistance and voltage remain constant, the current flow will be constant. This relationship in simple DC circuits is expressed by this formula - E=IR (volts = Amps X Resistance)

In the case of our starter motor, we introduce some new terms like impedance but the concept is similar.

When power is first applied to a motor, the resistance in the windings is not very high and so there is an immediate high current flow. As the rotor begins to turn, we begin to introduce other things like inductance and capacitance that have an effect on resistance. The combined resistive characteristics of resistance, capacitance, and inductance is termed impedance but the effect is very similar. This impedance increases as the motor rpm increases and so current flow decreases with a constant voltage being applied. This is that "inrush" current you have probably heard about before. Once the motor is turning steady, the impedance stabilizes and so current flow becomes stable.

Notice that the capacity of the power supply hasn't come up. That's because the capacity of the battery determines how long it will be able to sustain the 12vdc potential. We use this rating when buying a deep-cycle battery for our boats. It helps us compare one battery to another and make a more educated choice for our needs.

Notice also that the CCA of the batteries has not come up. Batteries typically don't like to be discharged rapidly. This causes heat and heat destroys. Starting batteries are a special breed designed to handle it to some degree but to what degree? How would we know the difference when making a purchase? I wan to use a battery to start a big diesel motor. Do I use one rated for 200CCA or 1000CCA? This where CCA ratings come into play. CCA tells us that the battery is designed to safely handle a certain high current load without causing damage to itself.

Bob

[BobT]

You might also add that, using an automotive type battery (with greater CCA's) gives the operator the opportunity to crank the engine over longer than the starter is designed for, thus potentially shortening the starters life.

That's a very good point and I neglected to mention it. Starter motors are placed under heavy load conditions and this means they rarely get to operate at their "normal" range. The heavy load adds resistance to the rotor's ability to turn and so, if you recall from my previous post, the slower turning rotor means lower electrical resistance and therefore higher current. Current flow generates heat in the motor windings and heat destroys.

Bob

[Dave S]

Now that I read Bob's post (and Phred's), I suspect the stories of people I hear burning out their starters in cars (from high CCA batteries) are more from continuous cranking instead of 10-15 second cycles.

Thanks again Bob.

[Roofer]

Remember we are connecting to a battery, not the starter.

Google "jump starting motorcycle from a car"

You will find this........

A car battery has more amperage, and the charging system for a car is much more powerful than that of a motorcycle. When jump starting a motorcycle from a car, DO NOT START THE CAR'S MOTOR because the extra power from the charging system will possibly destroy the motorcycle's charging system and could cause a fire. The car battery should have enough power to start the motorcycle without the car's motor running.

The explanation on the other posts are informative, but don't pertain to the situation.

[BobT]

I can see where you're going and could agree with this, in a situation where the ATV battery has been drawn down a lot. A battery with a low charge has less resistance than one fully charged and therefore, the battery would also demand power from the car charging system as well.

However, there is a point to where I might disagree and someone with more battery knowledge may be able to enlighten me. Even a battery with low CCA rating can deliver extremely high current if it is demanded. Drop a short circuit across the terminals of any battery and you'll see what I mean. It still revolves around the load demanding the current. The load from the low battery plus the load from the starter trying to turn add up to the load seen by the car. Whether the car is running or not, the load is still the same and the battery will try to deliver.

Edit: I would be more inclined to see a higher risk to the car's system than the load.

Bob

[BobT]

In reference to the original post, I will share a rather embarrassing situation that occurred to me last winter.

In almost 40 years of driving I have never before experienced this situation. I have always been able to do most of my own automotive electrical/mechanical work. At least until the introduction of computers and the testing equipment necessary.

30 years ago things were much simpler. You had a coil, points, condenser, rotor, distributor cap, wires, and plugs. Inexpensive stuff to replace if necessary and easy to tell when they needed replacing.

One huge advantage today is that the system delivers much higher voltage to the spark plugs which means wider gaps, hotter spark, and engines run far cleaner than they ever did.

The only time I had ever heard or experienced fowled plugs was either by running a two-cycle engine too rich or by flooding a four-cycle. In the latter case, you just opened the throttle and turned it over until it ran or you just let it set for a couple hours and then do it. This usually did the trick.

Last winter I fired up my ATV and drove out on the ice. I shut it down, fished for about an hour and then decided to move. I fired up the ATV and pulled my portable about 100 yards and then shut it off. About an hour later I tried to start it but no go. Just a little pop or backfire once in a while. I tried everything. Even using the recoil and electric starter at the same time. It was late enough in the year I walked back to my truck, drove out, and hand loaded the ATV onto my trailer.

The next day I tried it again and still the same thing. I figured I had something wrong with my ignition system so I took it in. The mechanic listened to my story and then tried starting it. In less than 30 seconds he diagnosed the problem as a flooded spark plug. I left it with him and the next day he called to confirm his findings.

It cost me nearly $100 to replace my spark plug!

Then he told me how he diagnosed the problem. When I told him my story, he realized that the day I was fishing it was only about 5 degrees. From this he assumed that I most likely had to choke my engine to get it started and then use it in a half-choke until it warmed up. Since I only drove it for about 100 yards before shutting it down, I was still half-choked and this was injecting excess fuel into the cylinder and so there was some unspent fuel that was probably building up inside the cold engine.

He recommended that any time I use the choke, I should at least run the engine with the choke off for a few seconds to clean out the cylinder before turning the engine off. Better still, leave it run long enough to warm up.

Expensive spark plug but I also got a few other things taken care of in the process because he found and repaired a leaky oil seal and welded my cracked muffler bracket.

Something to keep in mind.

Bob