My suzuki king quad just shuts off while riding ,but will starts right back up,its like someone turned the key off any ideas what might cause this.

Check for a broken wire around the steering column.

Loose ign switch or bad ground loose or dirty ign fuse

It is electrical for most of the time. There are wiring and contacts that tend to corrode over years of mud and moist exposure.

Check fuel filter

First, there can be two primary reasons for the shut down and restart. 1- fuel related. 2- electrical. Either can cause this problem.
We'll start with the least expensive and easiest - fuel system. Make sure your air filter is clean and properly treated-( 7 years old - probably time for a new one)! Install a correct new spark plug.
Your fuel delivery works off gravity and open vents that allow the fuel to flow properly. Make sure the gas cap vent in not obstructed. This is what allows fuel to flow freely and uninterrupted from the tank. Make sure you petcock is clean inside and when attached to the fuel tank, in the on position, fuel flows freely and uninterrupted through it to the carb. If fuel is flow is good at this point, time to clean the carb AND ALL THE VENTILATION TUBES, some vent tubes have one-way valves at the end of the vent tubes to prevent water from flowing into the carb while riding in deep water. These valves can become clogged easily. Replace any that are clogged-new ones always work better! Any vent blockage is what will stop the free flow of fuel into the carb. Make sure the floats are good and the float level is set correctly (refer to a factory service manual). Many floats today are plastic and are preset. The next item, the float needle and seat assembly (this controls the flow of fuel into the carb as the engine requires it) may need replacing. I have cleaned, polished, resurfaced older all brass needles and seats, but the new needles have a rubber like coating on them which prevents any repair. I, personally, would replace this set as a precautionary measure. There are several SMALL vent passages cast into or drilled into the carb body. This cleaning should be done by someone WHO KNOWS what and WHY they are cleaning your carb (experienced professional!!!)
After you have had ALL this done. Ride and see if this has cured your problem. I feel that this will take care of it if your EXPERIENCED PRO has done ALL of these steps!
Follow me on fixya, let me know if this fixes your problem. If not, repost and we will start on electrical.