Hornby Merchant Navy motor problem

[Matthew-763196]

I am having running problems with a Hornby Merchant Navy "Canadian Pacific" R2171 from around 2003 I believe. Most of the time the loco runs fine at all speeds, but occasionally it will stop at slow speeds, even on straight level track sections - as if the motor is sticking. I have checked the current collection, this is fine - the loco tender coupling is "hard wired" rather than the factory drawbar connection, so it's highly unlikely to be anything to do with electrical continuity. The valve gear is not binding and the loco actually runs perfectly well even at very low speeds most of the time.

Has anybody else experienced a similar problem? - I'm wondering if it might be a fault with the motor but not keen to embark on replacement unless I'm more certain of this. Does anybody know if this motor - X4026 5 Pole - is prone to this issue?

Many thanks

Matthew

[96RAF]

X4026 is as close to a standard motor as there is in the Hornby inventory. It is fitted to more loco types than any other, so I guess it is as reliable as it gets. Any chance it is simply worn out.

I had to fettle the pick-ups on my MN as they were not very well designed especially the way one side is collected via a rivet and wire simply touching the pick-up and held in place by the chassis lower plastic bit..

[Matthew-763196]

Thanks for that, 96RAF. I have fettled the pick ups just as you have so I'm as certain as I can be that it is not a current collection problem. I doubt the motor is worn out as the loco has had very little use. The problem is so intermittent and so specific when it does happen that I'm just wondering if anybody out there has had the same thing?

If there's no break in the current collection, I'm thinking it can only be the motor...

[ColinB]

I have this loco but I can't remember how the pickups are wired and knowing how flimsy the valve gear is I am not going to take it apart. If it is like most of the Hornby locos of this era then the pickups press against a moulded casting which is about 2 mm diameter for one side and a brass solder tag for the other. Over the years this connection doesn't work that well, so what I get is some relatively thin wire and hard wire the pickups to these wires.