It sounds like your carb needs to be cleaned or rebuilt.
start with water pump. If its a V6 3.1L have the intake manifold gasket checked. You may have a coolant leak.
nevermind it ended up being the ignition coil
Low coolant Water pump not working properly Cooling fan not working Thermostat not opening fully Radiator plugged or dirty Check the radiator fan.
Maybe bad coil
1 300 rpm
you either have a cracked cylinder head that is leaking coolent into the combustion chamber causeing rough idleing and eventualy total engine failure. to check this pull out the oil dipstick and see if the oil is thin or watered down you either have a cracked cylinder head that is leaking coolent into the combustion chamber causeing rough idleing and eventualy total engine failure. to check this pull out the oil dipstick and see if the oil is thin or watered down
Check the EGR valve.
It is easiest to remove the thermostat and drain the radiator by removing the lower hose. Dispose of the coolant properly. reinstall the lower hose and run water from the garden hose through the engine with it idleing until it runs clear. Then remove the lower hose to drain the radiator and reinstall the thermostat with the spring toward the engine. Then fill the radiator with coolant and start the engine up and top off the radiator after the thermostat opens. You should end up with about a 50/50 mixture of coolant and water. Good Luck Joe
Some times when idleing in traffic the 250 can overheat, you should make sure your radiator is not clogged with stuff and make sure your idle is set to around 1200 rpms if it is overheating you should set it lower. Also make sure you have enough coolant, the resivoir is located under the left side fairing.
look for a loose vacuum line.
Probably have a misfire or lean fuel mix NELSON
Needs a recharge