YZ125 Shifter motor wont start, NO SPARK, ignition problem?

[PCRShifterKart87]

I was out practicing the other day with my shifter kart, which has a 1999 (i think) Yz125 motor and a PWM Keihin pump around carb, when the engine started cutting out while i was driving. I thought it was my leg hitting the kill switch mounted on the frame rails that hold up the steering wheel, but i never found out for sure so it might have been something with the ignition...

After that, i pulled into the pits and gave it a rest. When i tried to start the kart again, it wouldnt turn over no matter what i did. It didnt even sound like it ever ignited any fuel in the engine either. After a while, the tire would just lock up when someone tried push starting me (probably because the motor was so flooded by this point). After this, i pulled the plug and found that it was extremely wet. I also turned the rear wheels to try to get all the fuel out of the motor, and when i did, fuel sprayed out of the motor like a supersoaker... im not sure if this has ever happened to anyone out there.

I checked the plug next to see if it still had a spark, and sure enough there was no spark. I had another plug which i thought was working when i pulled it, so i checked to see if i could get a spark with that one, but i didnt see a spark with it either... I still heard the ticking sound like the plug was producing a spark, but there definitely was no spark from either plug...

Does anyone have any clue as to what this problem could be? I was thinking that it could be the stator because it was cutting out while i was driving (unless it was my leg that was hitting the kill switch). Could it also be the coil that went bad because i am not getting any spark out of it?? Could all this be caused by the CDI box going bad?? I dont think there is anything wrong with my carb, i just think i flouded the motor by trying to start it for so long (its a PWM Keihin carb with the pump around mod).

Please help! Im going to work on the kart friday afternoon, so i will give you guys an update and check the things you guys suggest.

Thanks in advance
Dave
itlnsilverado87@yahoo.com

[Rick]

Locking up when someone tried to push you is not good. Are you sure you didn't stick it? A couple of us will be at Norway tomorrow for practice and tuning. Did you ask Les or Andy about it?

[PCRShifterKart87]

Rick
I didnt ask anyone about it because i had to leave after it happened. The motor spins fine when i pull the plug, so i didnt stick it. Im just not getting a damn spark no matter what i do. I still hear a ticking sound, but no spark...

I wish i could make it tomorrow, but im out of town and wont be able to make it to Norway untill Saturday.

This is really dissappointing because i just bought the kart and only got 2 practice sessions out of it...

[Rick]

Is your battery dead? You might need to charge it.

[PCRShifterKart87]

No battery. Its a shifted kart with a moto YZ125 motor. Can Andy or Les chime in if they have any suggestions

[MotoBob]

If it is not a bad plug...
At a glance I would guess Stator. I had a few go out on YZ125 Dirt Bikes. The symptoms usually consist of running fine but cutting out at high RPM when it gets hot, unless it gave out all together. There is a way to take it off and let a bike shop test it. If it is not the Stator it could be the coil or CDI box. I don't think there are any other parts in the electrical system.

[JET Karting - Andy Finke]

These old shifter karts are a tough deal this way.

We don't do much work on the engines because they are so complicated and very few people run them anymore. When I did my shifter racing, I spent $3500 on the engine at the motor shop to make it run up front with new parts. Still had a fair amount of trouble. Expect to work on it a lot.

That said, I'd check the coil and plug wire first. I've seen these go bad more regularly than other parts, and for sure they are easiest to change! Try cutting the last 1/2 inch of plug wire off each end and putting it back. Sometimes the ends get corroded and don't transmit spark well. Especially likely on a kart that has sat for awhile.

If that doesn't work, I'm with MotoBob. Take it off the kart and to a bike shop. Or buy a whole ignition system and start swapping parts.


Andy

[avmaviator]

I talked to Dave a couple days ago and he said that it was a bad killswitch along with a bad plug.

Are they any shifter classes/racers at Norway these days?

You should join the ranks of TAG Dave!!

[Jeff Salak]

There is a good showing of shifter karts at Badger. Seems to me like 6 to 10 shifters there on average. Race just with shifters on track. Standing start. Awesome to watch!

[Jeff Stamper]

No, come on out to the big tracks this season and race in the Stock Moto class with us ! Should be a huge class ! DOnt know if the YZ will keep up with the Hondas, but its still fun, besides that, the TaG class at Norway is almost non existant