Fuel, spark, compression, timing but won’t start

[Russbuss]

85 ATC 200x has proper cam and spark advancer timing, it’s getting fuel, has compression, and has nice blue spark but it still won’t start any ideas? I’ve checked everything with a multimeter and doubled checked everything but it wont fire over at all!

[coolpool]

Seems like you've tackled most things but could it be 180 degrees off on timing? Or maybe the woodruff key on the flywheel is spun a bit?

[Russbuss]

Seems like you've tackled most things but could it be 180 degrees off on timing? Or maybe the woodruff key on the flywheel is spun a bit?

I’ll have to check the woodruff key is it left hand thread measuring clockwise to loosen?

[coolpool]

Sorry, not familiar with that engine but a manual should clear that up if you have one. I suspect it's a right hand thread as I've had them off on a 70 and a 200 Big Red and that's what I've found.

[shortline10]

Std threads , lefty loosely- righty thighty

Btw their are no reverse threads on the 83-85 200x motors .
86/87 200x their are though .

[HoldMyBeer]

Check valve clearance. Be sure you’re setting everything with piston TDC on the compression stroke. Take the plug out and hold your finger over the hole while you slowly turn it over. When it’s pushing air out of the hole you’re on the compression stroke.

[BarnBoy]

Check that your advancer is not 180° out
That'll cause this issue....

[Russbuss]

Valves are good

[deejaycee_2000]

Then it can only be your carb, take your air filter off and try spraying some quick start through the carb body so it reaches the cylinder, if it sounds like it wants to go after a few kicks, then you know all else is good you need to pay attention to your carb.

[Russbuss]

Tried starting it with no carb on and it still won’t start and I tried gas down the cylinder too which would rule out the carb if it ran

[gimmeamidget]

I still think it’s electrical. I know you checked the on off switch but I would put a meter on it and make sure it’s not shorting out

[Russbuss]

Tried it with the kill switch unplugged, also when I kick the motor one time it sparks once and has a blue spark, shouldn’t it spark multiple times for one kick?

[gimmeamidget]

Yes should spark many times per kick

[Russbuss]

Yeah what would cause that?, I tried a new spark plug, a Cdi and spark plug coil and wire from a running ATC 200x, pulse generator measures within ohm spec and so does the stator, stator put out 6-12 volts and when ohm testing it goes from 220 down to 216 over 10-20 seconds and then holds at 216

[gimmeamidget]

Did you paint frame? Is the coil making a good ground where it bolts to frame?

[Russbuss]

Didn’t paint it, but I sanded the ground where the coil mounts to the frame, the ground connectors and sanded the coil too all have good clean ground

[HoldMyBeer]

So with a new plug and working parts off another bike it only sparked once?

[Russbuss]

Yep, it only sparks once per kick, randomly it’ll spark more than once per kick but it’s random when it does it, and I’ve sanded every ground, continuity checked everything wire from the cdi pin and ohm checked everything from the cdi pins, everything measures within spec and I’ve checked and made sure the pulsar gap is correct to the manual and the cam timing is dead on, every 13 kicks it’ll pop once till the 17 kick and thing nothing and won’t start, basically it’ll pop once per kick from kick 13 through kick 17 then at kick 18 it’s back to nothing and it constantly does that too, all the timing is dead on and it’ll do that wether I used starting fluid or gas down the cylinder hole

[HoldMyBeer]

Just for laughs... have you tried to pull start it? I’m just curious what happens if you’re pulling it with something else, not kicking.

[HoldMyBeer]

I think I’d try a new stator coil, or at least test that one. Maybe you have? Be sure it’s putting out enough juice when you kick it. I’ve had stator coils fail before and everything else you listed is new or have tried with known good. Meter it when you kick it, see what it’s putting out on those kicks it doesn’t fire. Idk what else it could be? I hate electrical stuff

[Russbuss]

So I just checked the timing again and I had everything perfectly lined up but now 100 kicks later my cam timing has jumped from the T to the F, what could cause it to jump like that on the first kick? Maybe when I spun the motor over backwards on accident? But now when it’s on F the cam dot is aligned with the notch at the top and so is the spark advancer, and ideas, the chain isn’t super loose either I mean I can move it with my finger about a quarter inch and little but it’s firm and springs back into place

[ps2fixer]

To diag this problem right, you probably need some more specialty tools. Sadly there isn't a spec for peak voltage, but getting that addition for your multi meter would help trouble shoot the problem. Basically you'd get a reading from the stator to CDI, then compare that with the output from CDI to ignition coil. They should be similar, newer machines spec at 100v or higher as the min spec. My 350x tests at 80v and runs fine.

Check your multimeter leads to see if they look similar, generally there's only a couple types and this listing is the more common style. If you get this, what it basically does is charge up a small high voltage capacitor and your multimeter reads the DC volts off the capacitor even though the source power can be AC.

https://www.ebay.com/itm/DVA-Direct-Voltage-Peak-Adapter-For-Stators-Triggers/352785390745?hash=item5223a5dc99:g:iM8AAOSwl~hfH1R R:sc:ShippingMethodExpress!48628!US!-1

It's interesting that you're seeing it spark once per kick. I'd do the spark test again and put the machine in 2nd or 3rd gear and "push start" it and see if it only sparks once for sure, or if it's consistent. Also blue spark does not mean it's good spark, the yellow/orange is just 100% always weak. A proper spark tester gaps the spark about 6mm (1/4 in) to simulate the resistance of high compression in the cylinder. The PET4000 spark tester is a great tool to have around to validate 100% if spark is good or not.

https://www.ereplacementparts.com/tester-spark-p-2558231.html?gclid=CjwKCAjwlbr8BRA0EiwAnt4MTiTZ6w3 csWMManO8qoU3ZA0YLQmQXLC_BZQCdpPKAynXy63xpzo-uBoCK7AQAvD_BwE

On the topic of grounds, sanding the frame really doesn't do much, atleast on these japanese machines, the threads of the bolt, and the face of the bolt that presses against the ring terminal are the two connection points normally which is why it's painted from the factory but doesn't have grounding problems.

The stator testing isn't clear which wires you were testing, there's the lighting coil (~12v) and the exciter coil (spikes 100v+ but isn't going to pick up correctly on a meter). I assume the 216-220ohm test was the exciter coil which is in the spec (100-400ohm).

For the CDI, did you buy a Chinese new one, or a NOS Honda one? I'd stick with your original parts unless you find one is truely bad. No point adding more variables to the mix to make things harder to diagnose. Yes... sometimes new parts are junk, or they are listed/sold incorrectly.

Does the spark once per kick thing happen for both the new CDI and your original? Also same story for the ignition coil, does it do the same thing with both the known working and the one orig to your machine?

It sounds like you have a 2nd atc200x that runs, so I'd go the simple route and put the electronic parts one at a time on your known working machine to rule out which one(s) are bad.



Also a couple things to note, the lighting circuit has nothing to do with the ignition, and it sounds like you're already aware, but the kill switch can be disconnected to avoid that being a problem.

Assuming all the mechanical things are good, it should be between the CDI, ignition coil, or stator. All 3 could fail in a way to have intermittent spark, but the stator should show up in the ohm testing if you test it while it's messing up (bad connection/broken winding). The ignition coil is the same story, if the coil inside has a broken wire, it could do similar. The CDI could have a weak capacitor so it only sparks every so often, or the connector on it could have bad solder points and they are loosing connection. Of course a damaged harness, poor terminal connections, etc could be a factor, but your testing at the CDI plug should rule that out pretty well.

Good luck with the machine, ignition related issues can be pretty tricky sometimes. Also the spark advancer (where the pulse generator is) has 2 springs that holds the weights in. If they are missing, rusted apart, etc, that could throw the ignition timing way advanced, but you'd still get a spark every other rev of the engine.


Here's a simplified view point of the ignition system. The exciter coil in the stator is the power source, it charges a capacitor in the CDI, and the pulse generator sends a voltage spike to the CDI to dump it's charge into the ignition coil to create a spark at the spark plug.