A handcar does have some degree of pulling power however it doesn't have a coupler that allows for attaching rollingstock. This project is so very simple, just perfect for a beginner as a leisurely Sunday afternoon project. And it takes just minutes! This is also a good project to introduce a child or grandchild to the hobby! It is a real pleasure to see your favorite handcar pulling a few cars around even the simplest loop of track!
After cutting (even kitchen sheers work well here) a small piece of .060" thick styrene (dimensions are not critical), drill a small hole then glue the styrene piece to the rear of the handcar (CA may be a better choice than styrene glue here). Paint it to match the handcar body if desired. A dummy coupler, Lionel part #600-9090-018 (called "dummy" because it doesn't open) is just bolted on to the rear of the handcar, and now you have the ability to pull 1 to 2 cars.
The coupler was shortened, but for some handcars depending on the figures, the full-length coupler may be needed. When trimming the coupler, a hole needs to be drilled to accommodate the small bolt. Secure the nut with a drop of super glue after making sure the coupler pivots freely. (On non-Lionel handcars, some minor adjustments, either shimming or shaving down the coupler at the mounting end, may be necessary for correct coupler height.).
A weight does help with traction. The photos tell the whole story. While Petunia, Porky's girlfriend (at the front of the handcar), has her arms in the most upright position, open the handcar by gently prying at the rear end with a small screwdriver. The fishing weight is placed in the small cavity under the pump handles. The egg-shaped weight (lead-free egg-shaped fishing weight, approx 1/2 oz., by South Bend from Wal-Mart) fits diagonally within the space. Snap the body back on the chassis being sure that the weight doesn't interfere with the body being correctly seated on the chassis.
Remember that pulling rollingstock does put an extra load on the handcar motor, so it is wise to give the handcar frequent breaks and keep it lubricated. Replace the traction tire as needed for the best traction. Keep a few spares on hand. Many hobbyists complain about sporadic operation of their handcars. For good handcar performance, just keep the wheels, center rail wiper/rollers, and the track very clean. Use a cotton swab dipped in rubbing alcohol to clean wheels and flanges. A heavier build-up of gunk on the wheels is easily scraped off with a plastic fast-food knife, then cleaned with alcohol. An old tooth brush dipped in rubbing alcohol also works great for cleaning the wheels, but protect the figures (and yourself) from spatters. The track needs to be wiped down frequently. Almost all operational problems are a result of dirt! Robert sometimes uses blue window cleaner to clean his track, and it works very well!