Is this causing surging issue

Hi, mower is surging so I check fuel line, filters and plug. Opened the back cover and noticed the belt is really loose. In fact the entire unit is easy to move by hand. Is this correct or how is it to be. Appreciate the guidance on finding a fix. 5 hp 4 stroke Briggs, self propelled 14SZ.

Surging engine is different than surging you feel when driving.

Surging engine is usually lean, clean the carb, usually a partially plugged pilot circuit.

Surging when driving could be worn belt that is thin in a couple of spots.

Often occurs when belt is slipping on the pulley briefly causing a thinner spot, thinner in width.

http://bionicengineering.net/media/JD_14SB/JD_14SB_Technical_Manual_Tm-1471.pdf make sure governor spring is attached left side of engine as well as governor arm bolt is tight & secure. You may need to remove carburetor & purchase correct rebuild kit & install after cleaning carburetor with carburetor cleaner. Also check air & fuel filters for replacement. For safety remove spark plug boot before working on engine.

Find Your Briggs & Stratton Manual: Small Engines just enter your engine numbers & pull up engine operators manual & parts list for your engine.

Everything needs to be tight, check belt for replacement, always use JD OEM parts. Take your time & be patient.

Great advice, a remaining question on this, should the belt be loose as shown in the attachment ? Also, the pullley and housing are loose to the touch. I can't identify and bolts to tighten the housing nor the belt. Thanks