Why dose my pit bike keep fouling sarkplugs

Rings or oil in the gas.

pull cover on magneto and check for loose pickup coil.

Unclip ignition barrel will kick over

What is causing the fouling? Engine oil? On a two cycle dirt bike, the fouling can be caused by excessive oil in fuel mix. I believe 50 to 1 is the correct ratio yet you may want to cut back, a little at a time, on the oil or run hotter fuel. The exhaust system will also accumulate enough oil sludge to impede the exhaust flow causing poor performance and plug fouling. A two cycle must breath freely to keep itself internally clean. Air cleaner to exhaust. Proper fuel mix should have little , very little. Good Luckand hopefully this helps you.

usually 2 strokes foul plugs when the oil is two strong in my old bike i mixed the gas 40:1 try that and if it dosent work i would take it to your nearest dealer and get them to check it out

Your bike may be jetted too lean. A common problem in these days of overzealous EPA regulations. You can tell if when you've cranked your throttle wide open and it splutters, if you back off on the throttle about 1/8 to 1/4 turn, it clears up. This is indicating that it is jetted too lean. When you close the throttle slightly, the fuel is being metered by the main jet and by backing off on the throttle a bit, you're cutting back on the air, thereby bringing the mixture closer to what the engine needs. Try rejetting the carb, Go up one or two sizes on the main jet, one step at the time.

Now, it could be too rich as well. If it splutters and blows black smoke out the exhaust, it either jetted too rich or the float level in the carb is set wrong.

Take care of the simple stuff first before rejetting the carb. Make sure your spark plugs are the correct ones and they are not fouled from overusage of the choke or enricher. If you allow the bike to "warm up" with the enricher on, plug fouling is common with this practice. I get the bike started and as soon as it will run without the enricher or choke on, I turn it off and keep the bike running with the throttle. Don't foul as many plugs that way.

Are you losing gear oil.
When the crankshaft seal leaks, oil from the gearbox is sucked into the crankcase, and this can foul the plug.
Also check the plug gap, most guys set the gap too small. It should be 0,7mmto 0,8mm. The plug should be a B9 EG, or equivilant.
Now, you can also change the plug cap to a type that has a built in resistor, this also helps with plug life.
Note that 2 strokes use plugs way more than 4 strokes, and you should replace the plug every 15-20 hours to keep your riding pleasant.
Good Bike you have there
Cheers
Jon

what should I do?Check the fuel tank petcock position. Check that the valve is in the proper position for fuel to flow. It happens. It's possible that the spark plug is fouled. Remove the plug and inspect for evidence of fouling. Clean and replace and then try starting the engine.,