Will be heading over later to nuke em's garage (which i have to my self while he is in north dakota) to start working on his 125 atc. He bought it real cheap from a nieghbor i believe in montanna. But it would run pretty good for 10ish minutes and then would die, but would start again after a few minutes. won't start at all right now but am gonna work on it. Will post more details and pictures later because everyone likes pictures

I would flush the fuel system, check the connections on the coil, and maybe swap the plug too. Good starting place to try. Pull the plug and pull start to check for spark to start!

that's actually is exactely what i was going to start with lol

No spark, does anyone have a manual or pdf. for the electrical system for an 1985 125cc?

Had no spark on my 80 ATC110 once, similar to the 85 125, I just started unplugging electrical connections and checking then plugging back in, one of the connections that even looked good was not just unplugging it and plugging back in fixed the spark problem.

Check all connections including grounds, remove the spark plug and test for spark after each connection, use a known to be good spark plug for testing, NEW PLUG does not mean its good test the plug your going to use on another machine to ensure it has spark.

3 wheeler site guys will have a manual I assume...

He fixed the spark problem...you gonna tell him, or should I? LMAO!!!!!

Moving on to fuel items...

Had the key or switch off?

Engine run switch at off. hehehe, done that before, just no witnesses!

Been their done that myself, once during a Pilot race in the tight woods I managed to turn off the Pilot at the red kill switch on the yoke took me a while to figure out why the Engine died, covered that switch with duct tape for all future races

Glad it was a easy fix, is it running?

Pics?

Pics to come hoser, although most are with a cell phone. got it to start again and seemed to fine, got nuke ems son and one of our friends to go ride around on garys track, and it did fine for me but kept dying on his son. i did an experiment and found out that if you keep on the throttle, it runs fine but when you let out on the throttle, it dies. My theory (probably wrong) is that it is jetted to rich. Any other ideas?

The idle screw is set properly?

Try to make it idle by applying some choke, if it will idle then the idle circuit is probably dirty, dirty slow jet.

Both jets looked clean, but i'll check again. i pulled the slide out and the c clip on the needle was set one from the top. should i try and lean it out or make it richer? or check the jets first?

With the Engine warm.

First try to adjust the idle screw this will raise the slide and the RPM should increase if not then try applying some choke this will give it more gas if the idle goes up you know its starving for gas at idle, if the idle does not go up and goes down and or runs rough then you know its getting too much gas at idle.

If its not getting enough gas then look at the jets again look real close with a bright light and magnifying glass if needed the hole in the slow jet is small.

[/qoute]With the Engine warm.

First try to adjust the idle screw this will raise the slide and the RPM should increase if not then try applying some choke this will give it more gas if the idle goes up you know its starving for gas at idle, if the idle does not go up and goes down and or runs rough then you know its getting too much gas at idle.

If its not getting enough gas then look at the jets again look real close with a bright light and magnifying glass if needed the hole in the slow jet is small.[/quote]
Alright, i Cleaned the living hell out of the carbarator. Now when i pull the choke the idle does speed up. It seemed to run pretty good for a while but still died out. i think now it is either to rich or to lean. Am done for the day today, so will go back tomorrow. and sorry hoser can't load pics right now. Will try tomorrow. thanks for the help

i'm just at a loss now. i came over today around 4:30ish mountian time to see if i could figure out what was wrong with the atc. but to my suprise it ran fine. idled beautifully, ran perfectlly. it ran fine until it seemed to start cooling down here but that could just be a coinsidence. it would run choked, but if you un did that it died. pulled a check bolt that was behind the fuel petcock, and it seemed clean. took it for a lap and it did fine. until i got back to the garage where it would start and idle but as soon as you put it in gear and gave it gas, it stalled out. started it in first gear and it seemed to go fine. i'm just at a total loss with this thing lol. to make matters worse i was planning on taking this thing camping this weekend so i'm at a race with the clock as well.

Vent in the gas cap plugged?

Maybe if you ram it with a 350 it will fix it

Don't tempt me! I'll do it i'm crazy!

Same like problems with a atc110. It was the gas cap.

Does your trike have electric choke?

No its a cable choke. That makes me wonder, i don't remember any vent on the gas cap at all...