# Turns over but no start, now what?



## Lonesome00 (Feb 8, 2013)

My 1989 Yamaha Pro-Hauler quad is giving me some trouble. It has been hard to start for a while. It use to start very easy. I would just bump the button and it would start right up. Even when it was cold or had not been run in a while I could trust it to start right up. I have charged the battery, cleaned the carb, tank, air box, and filter. I even changed the fluids while I was at it. This thing would start on staring fluid but that does no good now either. Now it just turns over and nothing more. I just checked for spark but nothing. I thought the plug might be bad but the spark tester I used did not light up either. So I am guessing it is the coil. Oh, I did check the fuse and it is good.  I cannot throw parts at this thing right now so what else should I check? How do I check the coil? Is it possible the plug wire is bad?


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## Backlasher82 (Feb 8, 2013)

The plug wire is stranded, they don't go bad unless you cut them. Plug caps do go bad if they're resistor caps and most are on ATVs and bikes. You can unscrew the plug cap from the wire and test it with an ohm meter, it should have about 5K ohm resistance.

Coils rarely go bad but you can use your ohm meter to test both sides of the coil, you can probably find the resistance specs online. Normally you test the coil with the plug cap removed. Get the specs for the stator coils too and check it at the connector, they go bad more often than the ignition coil due to the heat in the motor.

Check the wiring connections and kill switch too.


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## Lonesome00 (Feb 8, 2013)

I have inscrewed wire caps before. But this one will not move. How do I remove it? I am afraid I will break it.


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## Backlasher82 (Feb 8, 2013)

Lonesome00 said:


> I have inscrewed wire caps before. But this one will not move. How do I remove it? I am afraid I will break it.



I was thinking it may have been an aftermarket cap that didn't unscrew but if you're worried about breaking it it has to be a plastic one, probably stock. It is probably stuck or corroded on the wire. Slide a small screwdriver or similar between the wire and the rubber boot on the cap, then insert the tube on a WD40 can in the gap and squirt some lube in between the cap and wire. You should be able to unscrew it then. Might have to use a rag to hold the wire but the cap isn't made onto the wire, it will unscrew.

Edit: you can also take the rubber boot on the wire side of the cap and slide it up the wire to get better access to the cap. Whether you reuse the cap or not, cut about 1/4" off the plug wire with dykes to get rod of any corrosion in the wire and give the plug cap a good connection.


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## Lonesome00 (Feb 8, 2013)

Thanks, I will give it a shot.


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## NE GA Pappy (Feb 8, 2013)

I'm betting the kill switch is shorted out.


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## Lonesome00 (Feb 8, 2013)

I never thought of that.


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## fishbait (Feb 9, 2013)

Probably the source coil or trigger coil. If its been getting harder and harder to start. Probably has not been running real good either? Long time heat soaking will kill these to parts on a yamaha.


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## Lonesome00 (Feb 9, 2013)

I was thinking along the same lines.


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## rayjay (Feb 9, 2013)

It probably has a CDI box that could be bad. The most surefire way to troubleshoot no spark issues is to park it next to a good running machine and swap parts back and forth until you isolate the problem. 

On my 'new' Gator I had an intermittent miss on the rear cyl that turned out to be a loose connector on the ign coil. Sometimes you get lucky.


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## Lonesome00 (Feb 9, 2013)

I wish I had naother machine like it. This one is super rare.


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## Backlasher82 (Feb 9, 2013)

The kill switch and the ignition switch go to ground to kill the ignition. The quickest way to test them is to just unplug them and see if you get a spark. If it doesn't have a pull starter, just jump across the solenoid to turn it over.

 Same thing on the plug cap. You don't have to check the resistance, just take it off and lay the plug wire on the head positioned so the spark can jump to the head.


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## Lonesome00 (Feb 9, 2013)

Thanks, that is a good idea.


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## Lonesome00 (Feb 10, 2013)

Update:
I cleaned the kill switch and now there is spark. However, it still just turns over and not start. It sounded like it tried a couple times but not by much. So, if it is still an electrical issue what could it be? How do I know if the spark is weak? I have not yet ruled out a mechanical issue yet. I will check the valve adjustment next. If that does not do it I cannot help but think it is a fuel issue. Which annoys me because I have already gone through the fuel system. However, something could have been stuck some where and decided to come lose after I put it all back together. Any thoughts?


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## GroundMan (Feb 10, 2013)

Glad to hear you have spark again!!! I hear and feel you on these pains, been there done that!

Just wondering if you have tried the starting spray since you have regained spark?


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## Lonesome00 (Feb 10, 2013)

I did not plan to. I want to find the root cause.


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## GroundMan (Feb 10, 2013)

I hear that bud. Just trying to eliminate carb issues like float adjustments, etc. I reworked a crotch rocket carb setup which consisted of 4 carbs. When putting them back together, I bent or mis-aligned the floats. This caused a big ol headache.

Not getting into talk of jets and ventri's (spelling) as you have already cleaned them.


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## Lonesome00 (Feb 10, 2013)

That is a very good point. I will check the float first.


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## Lonesome00 (Feb 10, 2013)

So, I decided to pull the carb and check it. I found a build up of crap inside. I must have gotten some bad gads at some point. When I pulled it apart I found a clogged pilot jet. I tore the rest of it down and got it so clean it looked like a new carb inside and out. I re-installed it and the same thing. It juts turned over and no start. I shot some starting fluid and it started right up. Once I got the idle set it stayed running. My problem is I still need starting fluid to start this thing. I guess tomorrow I am on to the valves.


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## Backlasher82 (Feb 10, 2013)

There is a passage in the float bowl that feeds the starter circuit, it could be clogged. Looking at the float bowl from the top it's a small hole in the gasket surface, you probably remember having to line up the brass tube with the hole when you put the bowl back on.

It has a 90 degree turn that gets clogged easily, you'll see the hole coming into the bottom of the bowl where gas enters. Spray carb cleaner into the hole to verify the passage is clear. You may have to soak the bowl to clean it.

Also, spray carb cleaner into the brass tube to make sure it's clean. If you didn't remove the starter plunger to take the carb off, pull the "choke" to open the circuit. If the plunger is out of the carb the spray will come out of that opening, if you just pull the choke it should come out of a hole in the carb throat on the engine side.


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## Lonesome00 (Feb 10, 2013)

I tore it all the way down except for the stuff that is pressed in. The passege ways you are refering to I cleaned and blew out with air. I let the bady, bowl, and parts soak in carb cleaner. I am pretty sure the carb is as clean as it can get. However, I am not certain everything is adjusted correctly. The seal at the top of the body where the cable goes through was bad. So I used one I had but is is thicker th eone that that came out. I am wonding if I should adjust the needle now.


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## NE GA Pappy (Feb 10, 2013)

If it will fire on starting fluid, you still have a carb problem. Don't go starting to adjust valve and such. You have to fix the carb first, and then you can tune it up later.  

Try turning it over with the breather box off. As you turn it, put your hand over the inlet neck to suck fuel up into the engine. Just do this for a second or two. If it fires, you need to make sure you are getting the choke to close up correctly. 

I am willing to bet money that the carb ain't as clean as you think it is.  I have had to clean them 3 or 5 times to make sure they are clean. 

The alky/gas you get now days will ruin a carb in short order. If you can find it, only use non ethanol fuel in it.  I only run non ethanol in my mowers, 4 wheelers, chain saws and stuff. The only thing I will put ethanol fuel in is my car, and I fill it up at least 2x a week.  Ethanol fuel that sits over 2 weeks will put water out of the air, and ruin a fuel system.


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## Lonesome00 (Feb 10, 2013)

I wonder it that is how the carb got dirty again. I will try the air box trick tomorrow. How do I check the choke?


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## NE GA Pappy (Feb 10, 2013)

it depends on the carb. Does it have the flap type choke or the plunger you lift to open the choke circuit. If it is the flap type you can just look in there and make sure the flap is closing all the way. The plunger type has a separate fuel circuit that has to be cleaned and checked.


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## Lonesome00 (Feb 10, 2013)

It is a plunger.


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## NE GA Pappy (Feb 10, 2013)

then you will have to trace that fuel circuit back and make sure it is cleaned out good. When you cap your hand over the inlet horn, it will suck fuel through every port, so it won't help you clean the circuit, but it will tell you if you have a choke problem


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## Lonesome00 (Feb 10, 2013)

I am not sure I follow. I will have to try it and see, but from what I am picturing, I do not see how I will know if the fuel is going through or not.


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## NE GA Pappy (Feb 10, 2013)

just cap your hand over the air inlet for a second or two, while turning it over. Then take you hand off and let it keep turning. If it doesn't start in a few seconds, cap your hand over the inlet again and repeat.  It will start when it sucks up the fuel


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## Lonesome00 (Feb 10, 2013)

I see now. Will that tell me if the choke is the problem?


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## NE GA Pappy (Feb 10, 2013)

It will help narrow it down.  I am betting your choke and low speed circuit are still not flowing fuel correctly.


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## Lonesome00 (Feb 10, 2013)

I used air to blow it all ou after it soaked. If it is clean, I wonder what the problem is. If it is not, I wonder how I missed it.


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## NE GA Pappy (Feb 10, 2013)

junk gas. the fuel you get today is trashy. Make sure you get not ethanol fuel for it. 

You might get air through it, but it can still be restricted and not be getting enough fuel through it to run right.


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## Lonesome00 (Feb 10, 2013)

I hope I do not have to pull the carb apart again.


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## NE GA Pappy (Feb 10, 2013)

You will. Just count on it. You may take it apart 2 or 3 more times before you get it clean.

bad news is , you may never get it clean. I have worked on one carb for over a week and never get it to run right. Sometimes it is cheaper to buy a new one.


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## Lonesome00 (Feb 10, 2013)

So far (crossed fingers) I have been lucky with carbs. I usually get them right the first time around.


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## Lonesome00 (Feb 10, 2013)

I take that back. I got stranded in Macon one day becuase I missed some junk in the carb on my motorcycle.


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## Napi (Feb 10, 2013)

Good advice so far. Check to be sure you have a good flow of gas from the tank. Pull the hose where it enters the carb and see if gas runs out the size of the hose ID.


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## Lonesome00 (Feb 11, 2013)

That I did and it does.


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## Lonesome00 (Feb 11, 2013)

Soooooo. I pulled the intake and tried to start it. Nothing. I placed my hand over the carb and turned it over a few times. Then, I tried to start it again and it tried but nothing. I pulled the choke and it fired right up. I shut it down and let it cool down. I stared it again with the choke on and it started after turning over a few times. I put the intake back on and let it cool down and tried again. This time it was tough to start with the choke but it did as long as I worked the throttle. Now, it is real hard to start and back fired a few times. I could not tell where the back fried came from though. It was a puff of white and it did not come from the exhaust. I want to get this carb right before I move on to the valves.


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## Bilge Rat LT 20 (Feb 15, 2013)

The E gas corrodes the metal in the carb/ fuel system.
The carb has crud/ corrosion somewhere.
Get the carb clean, all the passages etc or buy a new one.

Outside chance of a vaccuum leak sucking air and not thru carb but not likley.

Valves are not your problem unless the motor is bad sick. Easy test for that is a leakdown test.  A compression test will give you a clue also.

Run non Egas in all small motors to avoid most carb problems.

Back fire can be a weak spark or rich gas.  Get carb right first then check spark and battery voltage.


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## Lonesome00 (Feb 16, 2013)

how is a leak down test done?


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## Backlasher82 (Feb 16, 2013)

Lonesome00 said:


> how is a leak down test done?



With a leakdown tester. You put the motor at TDC, screw an adapter into the spark plug hole and attach the adapter to the leakdown tester, then hook an air hose to the tester. The tester has a gauge that tells you the amount of leakage you are getting past the rings and valves. You can tell which is leaking by putting your ear to the intake, exhaust and either the oil fill or crankcase breather. Since your breather hose is routed to the airbox it would be best to disconnect it so that any air getting past the rings would be heard in the airbox and may make you think it's coming past the intake valve.

But your problem is in the carb. Or the fuel supply to the carb. Or both.


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## Lonesome00 (Feb 16, 2013)

I saw some where some one made a leak down tester with PVC I think. I cannot remember where I saw it but I would like ot know more about it.

I agree, but I would like ot check everything while I am at it.

I have been pretty busy with a sick kid now a sick wife. So I am trying to get to this quad inbetween other stuff.


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## Backlasher82 (Feb 16, 2013)

A leakdown tester is a very valuable tool for diagnostic, it can tell you more about what's going on inside your motor than a compression gauge. If you have a Snap-On compression gauge or similar style that has different hose type adaptors that screw into the spark plug hole and use a schrader valve that you can remove the only thing you'd need would be a way to hook the air up and a gauge to measure the leakage. 

My Snap-On leakdown tester gauge shows the leakage in percentage and has an air regulator to zero the gauge that is very handy but it could probably all be made yourself. Then again, you might find a deal on a used one on Ebay. It's not a tool you'll use every day but it sure can come in handy.


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## Lonesome00 (Feb 16, 2013)

I agree.


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## Backlasher82 (Feb 16, 2013)

Just for the halibut, I looked on Ebay. Without digging too deep I saw a Snap-on for $65 and an off-brand for $35 including shipping. You'd be hard pressed to make one for that.


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## Bilge Rat LT 20 (Feb 17, 2013)

Get the carb right first.

Proper fuel/air mix, spark, and compression make the wheel go round!!!


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## Lonesome00 (Feb 17, 2013)

That does sound like a good deal.

I will have to double check the carb.


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## Lonesome00 (Feb 23, 2013)

I think I found the problem.

The vales are correct, the carb is cleaner than new and I put brand new gas in it after draining it. I tried to start it again and nothing. I then figured maybe it is sucking air through the intake. The intake is a molded rubber piece with aluminum flanges on the ends molded in. I pulled it and found a tear that I could stick two fingers in. I guess that would do it.


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## Lonesome00 (Feb 23, 2013)

I cannot spend money on a new intake. So, I am devising a plan to re-use/repair this one. So far the only thing I have come up with a radiator hose. I can cut it to length then clamps it to the aluminum flanges. I would of course have to cut them out of the molded intake though. My issue with that is the intake supports the weight of the carb. So I may have to make a bracket to do that part.


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