Any way to rescue a chuggy loco?

[Relativenewbie]

Unfortunately, while I have a few locos that run well, I have a couple that only run in fits and starts when given a little push and at a high speed. I probably haven't shown them the most care and attention in the 5 years or so that i've owned them (bought new and worked fine), as they've been left out on the track for years. Are there any procedures that I (as an amateur) can do to restore them or can I take them to a model shop to have them repaired? Cheers

 

[90019]

If you're happy about taking the shells off, then try giving the connections a clean. Also make sure the wheels are clean as well.

 

[EM2]

A pair of tweezers to pick out any fluff that might have got into the motion, a mini vac or soft brush (old make-up brushes are ideal) for any dust.
A proper lubrication will never hurt, use a couple of drops of sewing machine oil or PECO Electrolube.
If you have a loop of track, try and run them in. Run them round the loop at a consistent medium speed for about an hour each way.