Please post a picture showing this matter to help toward a suggested repair. IMO, running w/o a spark arrest is a concern when you have possible fire conditions from exhaust sparks (as dry grass and etc in the area).

Well, here's a pic from Google, looks like the one below. Really just wondering if a spark arrestor is necessary on a new 4-stroke engine. Probably take at least a week to get another one.

Thanks!

{{gwi:320636}}

The spark arrestor itself doesn't affect the runability of the engine. It really does as the name indicates and is there to lessen the chance of fire from tossing a spark from the exhaust. You may be thinking of the practice not to remove a screen from a 2 stroke as some tend to remove them rather than to do proper maintenance or address the cause of the plugging- IE a rich mix or plugged air filter.