Thanks for the replies guys, I'll give the suggestions a try.

I received this engine for a Christmas gift.  All the features work but it doesn't run smoothly, (herky-jerky) especially at slow speed.  I lubricated the axles and rods lightly, wheels and track are clean.  Some internal mechanical binding is what I think.  Warranty card says fill out and return within 10 days of purchase.  This was a new ebay purchase back in July 2014.  Can I still send in the warranty card to activate the warranty then send the engine back for service?

Cliff Campo