Help with ZD28 Engine Issue

[Duckhunter]

My ZD28 is about 6 years old and has been great. Has about 400 hours on it and when mowing, the engine intermittently slows way down then returns to full speed. Reducing the load by stopping and disengaging the belt seems to help it catch up. At idle it seems to have a dead miss but catches back up when you return to full throttle. New fuel filter and clean air filter. Starts normally and this issue is happening more frequently now, it started as a once every 10 minute deal, now every 2 minutes or so.
Hope to find a solution so I can fix it myself. Any suggestions or history like this for yours?

 

[psdx]

Fuel filter?

 

[art]

I believe there is two fuel filters on those machines.

 

[tawilson]

Mine seems to be running a little rough so I just called my dealer and yes they have 2 and they are sitting on a shelf with my name on them.