Well a friend of mine is having me fix a small ATV for him. It's a 50cc 2 stroke mini Polaris Scrambler. I need to replace the fuel lines and oil line. Here's the problem. He said that when you ride it for to long, something would get to hot and it would quit. Then if you let it cool down it will run fine again. What would cause it to quit like that?

 

short answer= coil// when coils go bad they will quit when they get hot then after they cool they will run ok till hot again.

 

yep coil

 

well that's easy enough. lets see what those cost. i was thinking that might be the problem since i'm seen that on my 4 strokes.

 

When it quits, can you still spin it over? Could just be running lean as well, gets hot, makes it hard to restart. What's the plug look like? Any mods on it?

 

to be honest, i haven't even worked on it yet. that's a weekend project. now this has a seperate gas tank, and oil tank so how would i adjust it if it is lean? thru the carb? again, i haven't pulled the plug. and there are no mods.

 

Update- i did some work on it today. Fuel and oil lines replaced. New coils and plug. It will start and run for 20 seconds the die and then restart again just fine. it's getting spark and fuel.

 

OK, make sure you put a small fuel filter in the fuel line,like one for a lawn mower, guarenteed there is junk in the tank from old fuel. next take the carb off and you will need a needle or a torch tip cleaner, right in the center of the carb/after taking fuel bowl off/ there will be what looks like an aluminum tube, should see a jet, they can be tiny that is why you need a needle to clean it out, there should be another jet too to clean out, think its the idle jet, really tiny, make sure you can shoot carb cleaner through all openings, just a note/ you won't be able to stick a needle all the wat through the pilot-idle jet, it will have a small obstruction in there that is why they clog so easy, that obstruction is normal, don't know if it hurts to remove it so I wouldn't mess with trying to. alot of times old fuel will develop a scum on side of the tank and it only take a tiny piece to clog things up, we had a little KFX80 2stroker that would do the same thing. even after you clean the tank still use the fuel filter.

 

i have a inline filter on it. i had the carb torn down and blasted everything down with carb cleaner. i'll pull it back off and clean out the jets.

 

It's either getting too much fuel or running out of fuel.

When I said lean, I meant air to fuel lean, not oil to fuel lean. As in your air/fuel mixture is off.

So it will start and idle for 20 seconds or so and just die? Then restarts no problem and does the same thing? Are you able to ride it around? What happens if you go to 1/4 throttle or 1/2 throttle, can you keep it running by doing this (effectively going to a different fuel circuit on the carb).