Mansfield 160 extremely difficult to make it flush

I think that's hows it designed. 1.6 gallons per flush. Hold handle down for longer flush/more water flow.

indicates a problem rubber washer on the inlet valve
get in a plumber or get replacement rubbers form a quality hardware shop or plumber supplies
rubbers expand with age and jam over the small opening

Not sure about your brand but many toilets have a flapper valve inside the tank which needs adjusting or replacing. Try this U tube link
How To Repair Mansfield Toilet

1. Is the toilet plugged or partially plugged. I have removqed toothbrushes, combs, toys etc. from toilet traps so check for any obstructions.
2. Rust and scale buildup. The buildup of rust , sediment and or scale in the internal passages of a toilet can greatly affect their performance.clean the small holes under the rim with a small piece of wire. Use Limeaway or CLR to remove rust and scale. put some in the tank and flush toilet. Let sit for a while and repeat.
3. Improper venting or plugged vent. A toilet needs a properly vented drain to work correctly. Check the vent to make sure it is not plugged or in the northern climates frosted shut.
4. Mechanical issues. Is the flapper lifting high enough when flush lever is flipped. Is water at correct height in tank. If it is a pressure assist is water pressure high enough. Is pressure tank waterlogged.
These are just afew of the many things that can cause a poor flushing toilet. Hope this helps.

It is normal for these useless new tanks to do that. Won't even flush a piece of paper. Pull off the lid and make sure the little hose is in the overflow pipe, and raise the water level as high as you can. take out all the bricks and water bottles, and bowl cleaners. Then give it a try. It might do a bit better. Hope this helps.

Hi, you need new Mansfield 210/211 flush valves. They can be found on amazon.. here: Amazon com Mansfield 210 211 seal. I hope this helped you. Cheers

Try holding the handel down for a couple of seconds each time you flush.

Are your wast water pipes in your house vented through the roof? If they are maybe the vent pipe is clogged. At my father in-laws house the pipes are not vented through the roof like their supposed to be to vent sewer gas. they are not vented at all. Every time you flush it sounds like someone is downs stairs screaming. Something to do with air/ suction in the pipes.

the flapper isn't sealing right