I have just acquired a 1979 ATC70. It will start, run for a bit, then die out. I then have to let it sit several hours, and it will start again, run a few minutes, then die. I have dismantled and cleaned the carburetor completely. I have also replaced the spark plug, air filter, gasoline, and oil. I don't want to pay a professional to fix it. Any ideas where to start? I am thinking it might be an ignition problem, but I don't know. Something else I noticed, was that when the motor gets hot, it starts to smoke. I figured it was just dirt and oil on the motor, but I pressure washed it and cleaned it right up, and it still smokes when hot (until it dies). I suspect a bad gasket, perhaps, leaking oil onto the motor and burning? Help!

 

WELCOME TO THE FORUMS!!!

have you cleaned out your gas tank? Cleaning out the pit ****? also try running it with the gas cap off and see if it runs longer. Sometimes the caps will get cloged and cause vaporlock... Your rings are probably bad if it smokes when running!


HondaAtcRoxz

 

Ya. I have cleaned out the entire fuel supply system from top to bottom. I just tried it with the cap off, and it fired up, but same old same old. It will stall at idle, so you gotta floor it. It runs for about 3-4 minutes full out, but as it warms up, it starts getting lumpy, and the revs start to slow down until it finally quits. I suspect you are right about the rings. I think a compression test is in the very near future...........

 

What does your plug look like after you do this??? It might be your stator going bad. You need to get a hold of a manual and ohm out your stator...

 

OK. What's a stator? Also, I have seen where some people install an aftermarket CDI ignition? I have no idea what that is, either!

 

I just checked the spark plug. It is soaked with gas, and black with carbon. There is maybe only 15-20 minutes of run time on the plug.

 

lol well its the wires comming out of the bottom end of your motor (some people call it the generator). The cdi box is the big black box its basicly your atcs computer that your generators computer.

 

So, to access the stator, I guess I have to pull the side of the motor right off? Those "wires" come out from under that aluminum cover, right beside the rip cord.

 

thats right... unplug the wires when you get a manual and ohm them out to see if it truley is bad.