Hello All


I have a 2002 SP 700. The last time I rode it and put it away, it seemed to be running fine. When I recently tried to start my bike, I could not keep it idling by itself, and it was very rough sounding. When I tried to give it more throttle, it would sputter, lose power, and stall out.

I did a little checking, and I determined I was not getting a spark to the left cylinder (as sitting on the ATV). First I tried a new plug, and then I used a Spark Test Indicator. Both showed there was no spark coming through the plug wire. I called my local dealer, explained the situation, and they recommended that I replace the Ignition Controller Unit (Ignition Coil and 2 plug wires with boots).

I replaced the Ignition Controller, and to the lack of my surprise, it did not fix the problem. I still have no spark to the left cylinder. While I was fiddling around, I noticed that my thumb throttle lever has a slight bit of play in it, which I had not noticed before. For about the first quarter inch or so, there is no tension on the thumb throttle lever. Beyond that first quarter inch, the thumb throttle seems to feel normal. When I move the thumb throttle within that first quarter inch, the motor (right cylinder only) revs very quickly, however, as soon as I go past that point, the motor starts to bog down, sputter and die out.

Are these two issues related to each other in some way?

Does anyone have any ideas of what to check, and how to check, the next several steps of troubleshooting the no spark situation?

Does anyone have any ideas of what to check, and how to check, the next several steps of troubleshooting the thumb throttle lever issue? Thank you for the assistance!



Chip

 

I do not know alot about the 700 but I had it happen on my sled and it was the CDI I blew one side out so if you have access to another 700 try changing them and see if it works it should only take a couple of minutes and rule it out or fix it either way it is a shot

 

Hello Alpine2

Thanks for the reply.


Isn't the Ignition Controller basically the same as the CDI on a SP700? I don't see a CDI unit in the parts descriptions, only the Ignition Controller (which includes the ignition coil, the plug wires, and plug boots). And yes, I did replace the Ignition Controller with a brand new unit, and it still does not fire on the left cylinder.

Any other ideas?

Anyone else have any information they can help with?


Thanks again.

Chip

 

It's been a while since I had my magneto cover off, but it seems there is only one pickup coil, so you can rule that out (since the right side is still sparking). That should also mean you can rule out the stator. Like your dealer, I would have suspected the CDI. Are all the wire related to the ignition connected? Everything good and grounded where it should be?

 

How did you determine the left side cylinder has no spark??? I would use an hei spark tester like used to test automotive ignition systems. It looks like a spark plug, and it has a spring clamp attached to it, and no neg. electrode attached at the end wheere there would normally be threads. It will require as much spark as a spark plug that is under compression and wet with fuel. you can use a standard spark plug but it may not be a true test. I had to replace the rubber boot that attaches the carb to the cylinder head on my '03 sp600 when it only had about 1,000 miles on it. It had started to crack and developed a vacuum leak. It was idling very rough like it had a missfire from a bad plug. Did you try swapping the spark plugs from side to side to see if the problem switches to the other side... how old are the plugs???

 

When I tried to start my ATV, I had problems keeping it idling, and it was extremely rough. I could tell both cylinders were not firing by the sound.

I used brand new spark plugs for the testing, two different plugs actually.

First test was to ground the plug to the motor or frame and then crank the engine and look for spark.

Upon failing this test with both new plugs, I tried a second type of test.

Second test was using a purchased spark test unit (basically a test light). Once again no spark was detected.

I performed the exact same tests on the "good" cylinder and could clearly see it was getting a spark.

As I wrote previously, I also put on a brand new Ignition Controller Unit, which includes two new plug wires, plugs and boots. Still no spark to the left side.


Any ideas why?


Thanks again.

Chip

 

did you know that there is a controller and an ignition coil?

 

Hey Silver Bullet,

Lookiing at my bike, and also the parts manual, there is only one Ignition Controller. Bought new, it comes as a unit with the two plug wires, plugs, and boots already attached. Am I missing something?? Thanks.

Chip

 

With this type of parrell twin , both pistons go up and down together [ a 360 degree crank] and produces an even firing twin [ fires every one turn or 360 degrees ]

These type of four stroke twins only have 1 pickup , 1 coil [ with 2 spark plug leads ] , and one ignition module

Because it's a single coil with 2 leads , both spark plugs fire at the same time and when 1 cylinder is on firing , the other is being fired as well but on valve overlap [ exhaust valve closing and intake is begining to open ]

If you have no spark across the plug gap on one cylinder but have it on the other then you must have a shorted spark plug or spark plug wire

With this coil design , if you disconect one spark plug lead , you won't see a spark out the other lead !!!!!

If this all checks out you may have a mechanical problem in the engine , Stuck valve ? ......... do a compresion check

 

Quoted from LenTech, "If you have no spark across the plug gap on one cylinder but have it on the other then you must have a shorted spark plug or spark plug wire."


Are you saying the side that is firing has the shorted spark plug? I ask this because I've tried several new plugs, and also two different Ignition Controllers, one of them being brand new. The right side has continued to spark the whole time, while the left side does not. So I am confused.


Chip