To long to warm up

Engine running cold.mean open.engine overheating ,stack closed.

I am assuming that you know this since the temp gauge is not reading at normal temperature. I say this because I have had people in the past tell me that the engine wasn't warming up only to find out that the real problem was the heater wasn't working. They are two completely different issues. That said, the primary reason that an engine won't come up to operating temp is that the thermostat is either

1. Stuck wide open
2. Not installed.

Code P 0125 indicates insufficient coolant temp to enter closed loop operation. Most likely cause is either engine is not warming up (stuck thermostat) or more likely bad coolant temp sensor is making computer think engine is not warm and thus sends excess fuel injector pulse making engine run rich. Very common problem which kills gas mileage and may make car run poorly. Easy part to test or just change.

There might be taps on the heater hoses

Is it normal that a new bike dies on you as you drive it? No way my friend. The carburetor should have a thermal-choke and it probably needs some adjustment.

how mutch engine oil do u pit in a derbi crosscity 125 my bikes 4 stroke

You might not be able to do much about this. It seems most manufacturer are concerned with reducing energy usage on washers. To that end, the biggest user of energy for a washer is not the motor, but the energy used to heat your water. Reducing the temp's will allow them to lower the energy used rating.
As an example, let's say you measure your cold water at a faucet and it's 55 degrees (of course this varies with the part of the country you live in. It is basically the average year round temp. Here where I am in Minnesota, that's about 44, but in Texas or Florida, it might be close to 70) Measure the hot at your faucet also, and let's say you get 125.
Now, if you measure the incomming water on your washer, the cold might be close to the cold measured at the faucet, say 60 in your area, but the warm might only be 70. Maybe not enough of a difference that your hand would even notice. Checking the hot, you might see not much over 100.
As I've said, the energy guidlines your government set forth are driving companies to make these type of adjustments. There is not much you can do about it short of re-wirering and possibly replacing the multi selenoid thermostatically controled water valve to make it into an older style washer fill system. The temp settings now are actually set to deliver temps which more accurately hit the ranges clothing manufacturers want when they say COLD, or WARM wash, in spite of your incomming water temps to the machine.

let the bike idle for the first min or so then give it a few quick burps on the throttle let it warm right up to operating temp then drive it go through the gears nice and easy first couple times after that you should be able to start opening it up and riding it like you normally would.

If jeep is a limited model it has automatic temp control for the heater blend door, it is controled by a electric motor, and can be problematic with age,sometimes it makes a clicking noise when the blend door is stiff ,which then it must be lubed and freed up