Hi guys and gals of the ATV world !

I recently traded my old go 7hp go kart or a 200cc 4-stroke Shenqi ATV. We got the quad not running, and took apart the top end to find the Piston rusted to the cylinder wall. My uncle and I sanded it down and cleaned both the cylinder and piston, but there was a VERY TINY bit of pitting on the inside of the cylinder. Annnnyways, we put the engine back together, cleaned the carb, and got a new spark plug for it. It's electric start, but when we try to start it ... it just won't fire up. It has compression, it's getting spark, getting fuel, and it's turning over but it just will not fire up.

We are thinking it is possibly the CDI ?? We just ordered a new one and it should be here soon but any other suggestions to get it running ? ANY HELP OR INFO. ON THIS KIND OF ATV WOULD BE EXTREMELY HELPFUL !!!!

Iwill put the URL of a Youtube video of the ATV so you can see my predicament more easily. Thanks !

__________________________________________________ _______
HERE'S WHAT I KNOW ABOUT IT SO FAR

200cc 4-stroke Shengqi/Zongshen/Lifan Electric start ATV.
Model number - HQ200-1

image.ec21.com/image/shengqi/oimg_GC00915854_CA00915919/200cc_ATV_Scooter_HQ200-1_.gif

 

 

so you've tested for spark, right? what color was the spark?
you're probably right about the timing/valve adjustments that you're contemplating.
spark plug wet with fuel?
have you cranked it and given it a small/short shot of ether/starting fluid to see if it tries to fire up? if it fires up and runs on ether/starting fluid, i'd think you have a fuel delivery problem.
if it doesn't start on ether/starting fluid, look at valves and timing.
i'm sure your CDI is fine if you have spark.
how did you test for spark?
does your quad have the safety interlock on the left handlebar brake lever? i presume your kill switch on the left handlebar is alright? just a few questions.

 

Yes it has spark, nice blue white color (checked with a new spark plug). When choked engine it gets fuel, enough to flood the engine. It wants to fire, it will sputter but not enough to "run". Double checked valve timing and its spot on. Checked compression with the finger test and i can not hold my finger over the spark plug hole to the point it hurts. What's confusing is that 1) its getting fuel, 2) its got spark and 3) its got compression. Could a bad cdi, spark, but throw off your ignition timing? Or is it that they work right or they dont. I cant seem to find any thing written about ignition timing on cdi systems except moving your pick up coil to avance your timing a few degrees. Also the stator is putting out 80 volts +. and 8 volts off the pick up windings. Is this exceptable? No saftey interlock switches that i have found. I have not tried starting fluid, just gas.

 

so it is flooding also? choke blocks air and sends more fuel than the normal pilot jet does. the pilot jet could be partially or fully plugged. double check your crankcase oil to make sure it ain't contaminated with gasoline. wait, is this a 4 sroke or 2 stroke machine?

 

i betcha it's a 4 stroke......nvm.

 

Yeah it's a 4 stroke.

 

I have done a thorough cleaning of the carb, twice.

 

Im thinking its a ignition timing problem. When i checked the spark to the compression/power stoke the spark looked very random. It was not a rythmic spark. There seemed to be atleast twice as many sparks as there should be. Could this be a bad pick up and the cdi is getting triggered from feedback from the ignition coil discharge?( bad cdi) Possable two stoke cdi? What else could cause random firing of the spark plug? The new cdi should show up any day, I guess I'll see then.

 

We got the new CDI in today and it looks like they original CDI was for a two stroke. We got it running now but we just need to fine tune it. Thanks for all the help.