So i was wondering i changed the spark plug on my bike including all oils, also included a costume yamaha fuel filter bike started fine rode it. Than second time i started it i forgot to turn gas line on..(my mistake) but i noticed as bike was turning off i turned valve on quicky as possible and bike bogged out would not start. i took sparkplug off agian and it was really oily black so i changed it agian..why did my spark plug give out like tht so quick and does it have to do with my new costume fuel filter and my human error..?

check the fuel flow and fuel filter.

start with the basic.
is there fuel air and spark
remove spark plugs check if there wet it means you tied to start for too long.
rest sparkplug on metal part of bike and turn over spark ok next is fuel remove carbs and clean ensure all passage ways are clean and moving parts are free to move.
check tank has been drained of fuel check for rust if rust present use rust remover or kream takes 3 days.
clean fuel filter.
clean air filters.
check that youre bike has no low oil pressure cut out if so clean oil filter and replace oil, check oil pressure is maintaining.
if in doubt lubricate wd40 and duck tape can solve 88% of problems.

UNDER the gas tank there is a lever, put in on.Maybe ur out of gas.

Chances are there is a water build up in the carb float bowls. The water comes from condensation in the gas tank. Try draining the carbs. Another possibility is carburetor main jets partially plugged up. You must clean the carbs if plugged jets are found to be the problem. Please rate my answer. Thanks.

Possibly a tune up including spark plugs, fuel filter, pcv valve, air filter, and an oil change. Do include the spark plug wires if it has them.
If all of that is fine, see if the spark plugs are covered in oil... that will also cause it to run bad but not necessarily throw the check engine light.
Good luck

Hi, Your motor bike has only 50 cc displacement and has no fuel pump with it. If you have problem with your fueling, just check and clean your fuel line including the fuel filter. Check also the spark plug for malfunction.
Regards. Please vote if this helpful, Jay

It may be possible that when it ran out of fuel that it grabbed any **** that was in the bottom of the tank and put it into the carbs, which may have gunked them up and they might need to be cleaned.

To verify that it IS or is NOT fuel or Carb related, get some starting fluid and shoot it into the air filter box ( or along the pod filters if the original box has been removed) to see if it starts. If it DOES start, you have a fuel issue either with the carbs being gunked up (idle jet or main jets), or the floats could be stuck open (again with gunk from the bottom of the tank) and thus flooding out your motor (you said it smells like gas). Usually if it smells like gas and the plugs are wet, something is wrong with the ignition since its not burning it. So if all of the above is OK, check the timing under the points cover, you may have to set the gap (on most older bikes its around .30-.40mm) But since you rode it home I doubt thats it.

How long since your bike was properly serviced? Service includes oil, oil filter, air filter, spark plugs, valve clearance check, fuel filter etc. Check for cracked PCV vent hoses around throttle bodies. checking of throttle body sync. These bikes usually run very well when properly maintained. Trouble starting when cold could be caused by many different things.

Good Luck!

yer change ya gear box oil and get all the old fuel out. just basicly anything you can clean or change do it!!! air filter,oil filter,water,spark plug and so on...and when you first start it let it warm up for bout 5 mins but no longer.