Eurostar 4 car and track set derails when going over points

[Jes TGU]

My 4 car Eurostar always derails when going over any points, except for the power car. My running theory is that the train is too light, because I have also been having issues with the train moving, as it will not start moving when told to via Railmaster, instead I need to push down on the power car and it then proceeds. Is it okay to put weights in the cars or are there any other fixes to some of my problems?

[96RAF]

Have a look at service sheet 325. There is space under the decoder socket and more weight could be added above the existing weights.

The other thing is does the motor sound as if it is turning and the wheels are slipping in which case the traction tyres may be worn or loose.

[Going Spare]

Before adding more weight, check that the bogies are free to swivel without restriction and that the distance between the inside faces of all wheelsets is correct at 14.5 mm. Also check that the plugs on the wires attached to the non-powered bogie of the motor car are making good contact with the wheel pick-ups, that those pick-ups are making good contact with the backs of the wheels and that both those contact surfaces are clean. Speed, of course, should be moderated when negotiating pointwork.