Good day and welcome to Just Answer. My name is XXXXX XXXXX X'X be happy to help you with your problem today.
What do you mean by "burning out"?... you are losing spark, or the plug is fouled?
the plug is fouling(gets black)
one mechanic thought it might be the pulsar
the three wheeler starts good (has electric start) and runs good until the spark plug fails, some times we've been able to clean the plug with a wire brush and it runs again, but most times after cleaning the plug it still wont run, until we replace with a brand new plug.
You can not clean a fouled plug.
A fouled plug is different than a a failing plug.
Plugs foul because of a rich fuel condition, lack or air supply to the engine, or due to engine wear & loss of compression.
Additionally, a lot of people over fill their engine oil & that leads to fouled plugs as excess oil is vented back into the crankcase.
I think you have a carb that is set up way too rich & you need your intake & exhaust valve clearances adjusted.