Limping Peckett!

[sb67]

I've been going through my loco's and I've a Hornby 0-4-0 Peckett that runs fine at speed but pauses slightly at low speed. The best way to describe it would be it looks like it's limping! The pickups, wheels and track are spotless so I'm not sure what else it could be or how to find out about it. I was wondering if it could be the connecting rods catching or something like that but I can't find anything obvious and have tried loosening them slightly but that hasn't helped. 

Has anyone else experienced this? 

 

Many thanks. 

[Flying Pig]

Try running it very slow and see if it always stalls with the wheels in the same place.  That would make a rod catching on something more obvious, but could also indicate a quartering error.  Or a bit of moulding flash on the back of a wheel catching a pickup.  Or a bit of moulding flash or hardened grease on the final drive gear.

[The Johnster]

Also, try loosening the keeper plate retaining screws a quarter turn at a time, then tightening by half a turn when the gear shows signs of getting out of mesh to ensure that the chassis is running as freely as possible in that respect.  And inspect the quartering; ‘limping’ can be caused by this being out a bit. 

[sb67]

Thanks for your replies.

I couldn't find any moulding flash anywhere but while inspecting closer the (not sure of the correct terminology)  valve gear was very slightly bent, and I think that was impeding the movement of the sliding bit. After very gentle tweaking, it runs a lot better.