Kids 125 UTV No Start

[dave5.0stang]

Hi I am new to the forum.  I have a small kids utv with a 125 4 stroke motor. It sat for over a year and I decided to get it running again.  Put a new carburetor on it and it ran better than ever. Change oil and fixed the brakes kids probably drove it for a few weeks maybe 3 to 4 hour maybe. Went to put it away after it sat for maybe an hour wouldn't start.  Just turns over no spitting or sputtering.  Checked compression has 150 psi, getting spark, changed spark plug old one was pretty black.  Put new cdi on and coil still nothing.  Any ideas would be appreciated thanks.

[Travis]

Put  a small amount (tablespoon or so) of gas down the Spark plug hole, reinstall the plug and wire, if it fires then dies, fuel system problem, sometimes fuel lines come apart on the inside and clog things up.

Then spray some gas into the carb via the air intake, if it sputters or backfires, you may have a valve problem.

If it doesn't fire off, there should be a black kill wire going to the coil. un plug it, then try to start it, if starts. The wire is shorting and grounding the coil.

[dave5.0stang]

Ok thanks Travis I will try it and let you know. 

[Travis]

Any luck?

[dave5.0stang]

Haven't got around to trying this yet.  Flooded with other projects coming in.  Hope to try it next week.  Thanks Travis keep you posted 👍👍

[dave5.0stang]

Still no luck Travis, any more ideas? 

[Travis]

Did it fire when you put fuel in the spark plug hole and reinstalled plug?

If not you need to locate the igniton coil, you'll need to remove the flywheel fan cover. Trace the spark plug wire if you need help locating it.

 There should be 2 wires on that coil. The spark plug wire and the Coil kill wire.  The kill wire is what you want. un plug it from the coil. reinstall the fan housing so you can start it.

 Then put fuel in the spark plug hole, reinstall the plug and spark plug wire, and try to start if it fires, there is something grounding the coil and killing spark, could be the wire has some insulation missing and shorting on something, or a faulty kill switch. If it fires and dies with the wire unplugged you also have a carb issue.

if you unplugged the wire and it still didn't fire, bad ignition coil.

Now, when the kill wire is unplugged and it tries to start and backfires and pops, you may have valve timing issue (out of adjustment) or a sheared flywheel key.

 

 

[dave5.0stang]

It did not fire when I tried your other suggestions. I have pulled the plug out with plug wire still attached I cranked it over and have some spark. Do you think it might be out of time for some reason?  Thanks for your input I appreciate it. 

[Travis]

I would check the ignition coil air gap to the flywheel, If you  can't find a specification i always set them at .010" thousandths.  And i would also remove the flywheel nut/bolt and check the key while your at it, as if the key is sheared it can throw off ignition timing.

Is the engine one of those Honda clone type engines?

[dave5.0stang]

Ya a 125