ATV won't start!

[fields_mj]

Battery charge has nothing to do with spark output. It isn't a car. Unhook the battery, pull with the rope and it should still spark

Good point. Not sure what was going through my head there.

I've jumped lawnmowers and ATVs off my truck several times with no problems. So long as they are both the same voltage, there's no problem. If the voltage is the same, then their's no electrical potential difference, and thus there is ZERO current flow, so it doesn't do squat to the battery. Now, if it's a 6V battery, there might be a problem.

I don't remember seeing a drain screw anywhere on my carb, but I also haven't had it out myself. I'll have to take another look.

The plug was black, but it is not now. A few minutes with a brass brush cleaned most of it off. The tip of the electrode took a few seconds with some fine sand paper. It is certainly fowling up, but I don't really want to put a brand new one on there just to fowl it back up again right off the bat. I'll get a few more of them on hand. I think I'm still going to order the ignition coil too. I checked last night, and it looks pretty easy to get to. Might as well get it done and over with.

 

[aleman]

Try this, shoot a little starting fluid to it an give it a try. If it starts for a sec then dies, you have a fuel problem(pilot jet)

 

[fields_mj]

Try this, shoot a little starting fluid to it an give it a try. If it starts for a sec then dies, you have a fuel problem(pilot jet)

Been there, done that. Didn't work. But, by the time I tried the Ether, the battery was about dead. It still should have fired off though, but it didn't. I'm sure that I have a fuel problem, BUT this is telling me that I probably have an electrical problem too.

Can anyone explain to me what the ignition coil is doing exactly? I know that it sends power to the plug, but mine looks like it's bolted to the frame. Looks like it has one wire coming it, but it was dark so maybe I just couldn't see a the other one. I would have thought that there would have been one wire that fed power to the coil, and one wire that was the trigger to release the power that is stored in the coil. I guess I just didn't see the other wire. I'm curios where the wires go so that I can check the connections and add some copper antizieze if needed for a better connection.

 

[tooold]

A quick and cheap spark tester is a clean(not black) spark plug with the ground tang removed. In free air, the ignition should easly jump a spark across the larger gap. If it doesn't, you have ign problem. Always use a plug that is not black, because the black is carbon and the spark will follow the carbon instead of jumping the gap. Being that your hand was wet with fuel when you covered the intake is a good sign because it shows you have fuel in the carb. There are 3 jets in the carb to check. The Main jet is for higher speeds and normaly doesn't get plugged because it has a larger orfice. The Pilot jet is much smaller and handles the idle circuit. The third jet is the enrichening circuit(choke) jet that is in the bottom of the float bowl, right down where all the dirt and water sits. I just worked on the neighbors woodsplitter that had about a cup of water in the fuel tank. When I worked at the Suzuki/Yamaha dealer, I would tell the farmers not to fill their ATV out of the outdoor fuel tank that they fill their tractors with. Many times that was causing carb problems such as water and rust.

 

[tooold]

Being that it has been recently worked on, I would double check the cam chain tensioner and the cam timing to make sure it didn't jump time. I would also check valve adjustment and operation of the compression release if it has one. At the dealership, when someone says it was just rebuilt and it's OK, that's when you double check their work with some simple checks.

 

[fields_mj]

At the dealership, when someone says it was just rebuilt and it's OK, that's when you double check their work with some simple checks.

That is SO VERY TRUE. Unfortuanatly I don't know squat about adjusting these carbs, so I have no way to check their work. That's why I had them do the work instead of me. I was going to have to have them set it up anyway.

For what its worth, I didn't just have a wet hand, I had a hand FULL of gas. When I pulled my hand off, maybe 1/4 cup of fuel ran out into the box. Maybe something is wrong in the carb and it's flooding itself out?

I've got an old clean plug. I'll take the tang off. For what it's worth, when I started out the plug was fowled and the spark was jumping from the back/bottom edge of the electrode to the side of the tang, so it was jumping a pretty big gap there. After brushing it off real good with a brass brush, it was still doing the same thing because the electrode and tang both had carbon on them. Once I got that cleaned off, the spark normally follows the correct path, but occationally jumps back to the base. I need to gap it again as I'm sure I messed that up along the way.

 

[joshua mason]

is it possible the choke is stuck and flooding it.

 

[hearnoevil]

I just had this problem on a 600 Grizzly, it's probably your stator they are famous for it.

Got mine at rmstator came with the gasket and everything, it was a easy swap, not a hitch after I swapped it out

 

[kodiak]

I've had good luck getting ATV related questions answered at atvconnection.com

 

[OH_Varmntr]

The fuel that was on your hand is normal. It doesn't mean it came from the pilot circuit though. It easily could have came from the main circuit. That was just to try to force anything out of the tiny passageways that may have gotten in there.

I just realized you're from Indiana. Where abouts? If you're close to me I'd be more than willing to come out and see what I can find. I graduated top of my class in motorcycle mechanics school in Cleveland back in '07.

I've jumped lawnmowers and ATVs off my truck several times with no problems. So long as they are both the same voltage, there's no problem. If the voltage is the same, then their's no electrical potential difference, and thus there is ZERO current flow, so it doesn't do squat to the battery. Now, if it's a 6V battery, there might be a problem.

Actually, when you jump a lawnmower or ATV, it's because the battery is dead, yes? If it's dead, then it does not have a full nominal voltage of 12.6VDC (2.1VDC per cell in a 6 cell battery). So yes, there is a difference in potential, which results in an almost instantaneous charging cycle of the battery to get it to match the voltage of the stronger battery.

You can ruin lead-acid batteries like this, and possibly even charging system components like the little grey box with cooling fins on it that serves to rectify and regulate voltage coming from the stator. Just because you haven't yet, doesn't mean you won't down the road. Best advice I can offer, whether you choose to go by it or not, is to only jump it with the engine off so the trucks charging system does not backfeed through the regulator/rectifier and fry the diodes, or worse, once that happens it can back feed into the stator and wipe it out as well.

Anyways, back on track.

You are obviously getting air. You are getting fuel, but just because you see/smell fuel doesn't mean it's getting the correct amount at the right time. Spark? Well there are insulation breakdown and resistance tests you can perform on the ignition coil and other parts of the ignition system to rule them out.

If you believe you are getting weak spark, you need to remove the plug wire from the plug and the coil. The wire will unscrew from the coil. There's a little brass stud coming out of the coil that the plug wire screws onto. It's the same way on the spark plug cap end. This stud makes contact with the wires of the plug wire. If I suspect that connection to be the culprit, I will take a pair of diagonal cutter (side cutters) and snip the last 1/4" or more off the end of the plug wire that screws into the coil or cap until you see good wire strands inside the plug wire. Once good, you can screw the plug cap back on, but leave the other end unscrewed from the coil for the next test.

If you have a meter, now is the time to place it on the resistance setting (Ohms) and stick one probe in the plug cap and the other probe into the coil end of the wire. You should see quite a high resistance, somewhere in the vacinity of 10k Ohms, if my memory serves me correctly. Reason being is there is a small ceramic insulator in the spark plug boot that has a very high resistance. If you are getting an Infinite reading or "OL" on the meter, then you need to take a flat blade screwdriver and unscrew the brass plug that holds the insulator in the cap. Remove the insulator, the spring, and oftentimes there's a tiny little spacer disk in there as well. A lot of times I'll find corrosion between the insulator and the spring. The spring is steel so it's first to corrode in there. Just for the heck of it, clean everything up with sandpaper and reassemble.

The link below will give you specs to check out the ignition and stator coils. They should be the same since most Yamaha ATV ignition systems are nearly identical.

How to Check CDI on a Yamaha Warrior | eHow.com

Atleast this will give you a direction in which to go. If you don't feel comfortable with doing any of the checks, you should really take it to a reputable shop/person to work on it.

 

[fields_mj]

I just had this problem on a 600 Grizzly, it's probably your stator they are famous for it.

Got mine at rmstator came with the gasket and everything, it was a easy swap, not a hitch after I swapped it out

I hope not. I really wasn't wanting to drop another $150+ on it, and I sure as heck don't have any time right now to swap it out. I need to be spending my time cutting firewood.

 

[lone wolf]

I worked late. By the time I got home and got the kids fed, I just now got it pushed back up to the garage (up hill, all the way). I did remove the air filter and covering the intake. I got a hand full of gas when I took my hand off. Does that mean the carb should be doing okay, or that it's plugged up?

I will certainly be getting some seafoam, and shutting my fuel supply off from now on. It generally sits for a month or two, not weeks. I use it in spurts, but when I use it, I use it.

If I jump it, I'll jump it off my diesel. No need to start it. If twin 1000 cca batteries can't give me a good spark, then I've really got some problems

The plug is less than 6 months old and has less than 3 hours on it. I did clean it up with some 120 grit, but I'm not going to replace it at this point. The last plug was also only 6 months old. The tech replaced it with the carb kit out of habit. That was okay, but I wish he would have given me the other plug back.

Right now, I think my biggest problem is the spark. Even if the carb needed cleaned, it should have fired on ether, but it didn't. No doubt I need to change my routine with my fuel, and I'll start off now with fresh gas and a charged battery, but in the end I think I'm going to have to put a new ignition module on it.

Thanks,
Mark

So you will try a new ignition but not a new plug?I got to tell you put a new plug in before you do anything like burn up your system with a Diesel truck.

 

[Misfit138]

All I am hearing points to spark, spark, spark..

 

[lone wolf]

All I am hearing points to spark, spark, spark..

I agree

 

[fields_mj]

The fuel that was on your hand is normal. It doesn't mean it came from the pilot circuit though. It easily could have came from the main circuit. That was just to try to force anything out of the tiny passageways that may have gotten in there.

I just realized you're from Indiana. Where abouts? If you're close to me I'd be more than willing to come out and see what I can find. I graduated top of my class in motorcycle mechanics school in Cleveland back in '07.



Actually, when you jump a lawnmower or ATV, it's because the battery is dead, yes? If it's dead, then it does not have a full nominal voltage of 12.6VDC (2.1VDC per cell in a 6 cell battery). So yes, there is a difference in potential, which results in an almost instantaneous charging cycle of the battery to get it to match the voltage of the stronger battery.

You can ruin lead-acid batteries like this, and possibly even charging system components like the little grey box with cooling fins on it that serves to rectify and regulate voltage coming from the stator. Just because you haven't yet, doesn't mean you won't down the road. Best advice I can offer, whether you choose to go by it or not, is to only jump it with the engine off so the trucks charging system does not backfeed through the regulator/rectifier and fry the diodes, or worse, once that happens it can back feed into the stator and wipe it out as well.

Anyways, back on track.

You are obviously getting air. You are getting fuel, but just because you see/smell fuel doesn't mean it's getting the correct amount at the right time. Spark? Well there are insulation breakdown and resistance tests you can perform on the ignition coil and other parts of the ignition system to rule them out.

If you believe you are getting weak spark, you need to remove the plug wire from the plug and the coil. The wire will unscrew from the coil. There's a little brass stud coming out of the coil that the plug wire screws onto. It's the same way on the spark plug cap end. This stud makes contact with the wires of the plug wire. If I suspect that connection to be the culprit, I will take a pair of diagonal cutter (side cutters) and snip the last 1/4" or more off the end of the plug wire that screws into the coil or cap until you see good wire strands inside the plug wire. Once good, you can screw the plug cap back on, but leave the other end unscrewed from the coil for the next test.

If you have a meter, now is the time to place it on the resistance setting (Ohms) and stick one probe in the plug cap and the other probe into the coil end of the wire. You should see quite a high resistance, somewhere in the vacinity of 10k Ohms, if my memory serves me correctly. Reason being is there is a small ceramic insulator in the spark plug boot that has a very high resistance. If you are getting an Infinite reading or "OL" on the meter, then you need to take a flat blade screwdriver and unscrew the brass plug that holds the insulator in the cap. Remove the insulator, the spring, and oftentimes there's a tiny little spacer disk in there as well. A lot of times I'll find corrosion between the insulator and the spring. The spring is steel so it's first to corrode in there. Just for the heck of it, clean everything up with sandpaper and reassemble.

The link below will give you specs to check out the ignition and stator coils. They should be the same since most Yamaha ATV ignition systems are nearly identical.

How to Check CDI on a Yamaha Warrior | eHow.com

Atleast this will give you a direction in which to go. If you don't feel comfortable with doing any of the checks, you should really take it to a reputable shop/person to work on it.

I'm down around Terre Haute IN, oppisite side of the state, but THANKS a TON for the offer, and all the free advise! I thought about the dead battery voltage after my post. I can see where it could cause problems if the battery is really low.

I'm not sure about my spark. On one hand, I can see it jump over 0.060" back at the base of the electrode when the tip is fowled, but I don't really know if that means anything at all. I went a head and ordered a new coil off e-bay for $25, and 4 plugs from the same shop while I was at it. If the problem is more than that, I'll have to run it over to the shop. I think my immediate problem is the wrong fuel/air ratio, but we'll see.

I picked up some seafoam at lunch today. Couldn't find the arrosol spray, had to go with the regular 16oz bottle instead which is probably better anyway. I drained the fuel when I got home, and found the stopper bolt on the carb and drained that out. I used a new tip off of a tube of RTV compound as a funnel and poured some seafoam directly into the carb via the fuel line. I flushed about an ounce through there, and then screwed the stopper bolt back in. I'm going to leave it in for a little while and then drain it out before bedtime. Would it hurt to leave it in over night, or even for a few days?. I cranked it over a few times trying to get the carb to suck some of the seafoam in, but it didn't take hardly any. I only turned it over 10 or 15 cycles. I had to do it with the pull rope which was a pain. It did try to fire a few times, which is encouraging. I forgot to bring my hobby charger home with me today. I was going to set it at 3 amps and let it trickle charge my battery. Tomorrow I'll try to remember to grab my charger home, and get some fresh gas. I need to get some more to mix for the saws anyway. We'll see how it goes.

Thanks!
Mark

 

[fields_mj]

So you will try a new ignition but not a new plug?I got to tell you put a new plug in before you do anything like burn up your system with a Diesel truck.

Naw, I was trying to avoid buying the coil, but since I ordered a coil for it today, I ordered 4 plugs at the same time. The sad thing is that the 4 NGK plugs off ebay will be $17 to my door, and the last time I bought one for it at Oreilly's I think they charged me over $10 for just one plug. To be honest, that was why I wasn't wanting to put a plug in it. Oreilly's is the only place in town that has the NGK plug, and I hate dealing with them AND they raped me on the last one. It's just me being stubborn. The plugs aren't lasting long, and I don't like the idea of dropping $10 bills on it left and right. If the store manager isn't there, they are okay to deal with, but that guy rubs me wrong every time he opens his mouth whether he's talking to me or not. The plugs were a lot less than $5 each to my door, so I ordered extras

Part of me says spark, part of me says that it's the wrong air/fuel ratio. The reality is that I don't have a clue, which you've probably already figured out by now. Since the plug isn't lasting long, I'm thinking that the fuel/air mix is certainly off by a fair amount, but that may not be what's biting me in the rear right now.

Thanks,
Mark

 

[OH_Varmntr]

Nope, it won't hurt to leave the Seafoam in the carb for the night, or even a few days. Can't really say how much varnish deposits it dissolves in a certain amount of time, but either way it won't hurt it.

The bad thing about trying to break things loose in the carb with a pour in cleaner is this. One the deposits are there, adding a cleaner doesn't mean it will break up everything to a small enough size to draw it through the jets/passageways.

Much of the time, it will barely start and stay running because there's junk partially blocking the fuel passages. Add a cleaner and it breaks all of that and then some loose, and when you try to start it again, if it didn't all dissolve then it plugs all the passages up tight and won't start at all after that.

But it's definately worth a try, especially if you are not confident enough to tackle a carb tear down yourself. :smile2:

Too bad you're so far away, it's been awhile since I've had a good day of troubleshooting an ATV/motorcycle. :frown:

Good luck though. We will help you as much as the internet allows. :msp_thumbup:

Edited to add: A spark plug in a 4-stroke should last a very long time. If you're fouling them up, you've got issues of having too much fuel somewhere along the lines.

 

[Craz z]

Just went through this on my dirtbike this summer. Gas will go to varnish in 1-3 months.

Question are you getting all this gas you're talking about on the choke circuit??

What i've noticed is that the choke circuit rarely if ever gets a complete blockage allowing a startup condition but once flipped to regular circuit the motor dies instantly.

if your varnished I can guarentee with 100% accuracy no bottle of anything will cure your troubles. You'll have to bust er open and clear the blockage by hand. I like to use welding tip cleaners for this just get the smaller size then the hole and don't ream out or use the file portion of the tip cleaner.

My bike was totally blocked and fouling the plug. Once I took it apart and cleaned all the circuits it came to life better then it had been for some time.

Weak spark isn't the greatest but if you got it to pop on ether then if you can get the fuel and air aka NOT on the choke circuit you'll be in business

Be very careful and take your time busting the bowl gasket free wouldn't hurt to have a backup on that and NEVER use RTV on a carb or auto tran one small flake of rtv will block small holes in one second flat.

PS the most important lesson ever learned working on mechanical items is always Know your basics are totally 100% verified before throwing 100$ bills on parts you don't need

Remember it worked the last few times you used it now it don't sounds like varnish to me. that would explain the erratic behavior before as the fuel isn't getting atomized due to blockage so raw fuel is introduced causing to run like crap my bike did the same thing for one season then it finally closed up and the only option is to get in there and clear it.

Some of those jets in there aren't much bigger then 3-5 human hairs so it don't take much to block it.

 

[Craz z]

One last thing that has been said many times already about your spark issue

A fouled plug can give a false positive for weak spark without a new one and seeing a weak spark there would be no reason to dive deep into coils and stators.

Also the sand paper method might get you by once but i've polished fouled plugs to perfection and still no start a new plug is so cheap even at 10$ could still save you more money then throwing bills at the wall trying to fix the problem.

Spark plugs are magical little things they either work or don't and visual inspections aren't good enough especially with todays iridium platnum titanium gold whatever they call em.

I just bought some marketing hype plugs for the saw they are no better then regulars IMO ive tried splitfires E3's and the latest easy starts which sucked too. good ole fashioned fat electrodes seem to resist the fouling better in my experience.

 

[aleman]

So did you ever fix it? What was the culprit?