The N Scale Mikado 2-8-2 is one of the iconic models of the N Scale Hobby. Its excellent performance coupled with excellent details made it immensely popular when it was introduced in the 1990s
Good Electrical contact is the key to smooth performance with any model locomotive. I have noticed that no two Kato Mikados perform the same, some are very smooth right out of the box and some move farther on your finger power than their own power. You can do some simple tests to see if your Mike is making the most of its electrical contact capabilities. Usually the tender does a pretty good job of picking up power but the locomotive falls on its face, so we'll start by testing the locomotive. First you will need to unplug the tender from the engine. Refer to Kato's instructions for replacing the draw bar, steps 1 through 6, to find out how. With the tender removed, place your locomotive on a section of clean, straight, and level track. Your engine should run smooth without stalling.
If your locomotive fails the test you need to test each drive wheel to be sure that power is getting from the wheels metal tire to the center hub. The power travels to the center hub through a copper contact strip on the back of the wheel. The contact strip seems to be just a hair short in some cases and doesn't quite touch the metal tire. Install a pair of contact wires with alligator clips to your throttle or power pack. Clip one of the wires to the tire without touching the contact strip. Clip one lead of a 12v light bulb to the other wire, I use an old light bulb out of a Bachman split frame GP40. Now turn up the power of your throttle about half way and touch the other lead of the light bulb to the bearing of the wheel with the wire clipped to it. If the light bulb comes on there is no problem, if it doesn't light up you'll need to fix the contact problem. Most of the time you can move the contact back and forth with a sewing needle and make connection. If the contact seems to be under the tire's lip you can sometimes pull the contact out from under the lip and gain contact on the outside.
If neither of these methods seem to work then you must remove the axle from the mechanism and then remove the wheel from the axle. Once the wheel is free you can remove the bearing and axle hub from the back of the wheel and the brass contact will come free. With a small drill bit in a low speed drill carefully oval out the hole in the center of the brass contact. Bend the arms of the contact in slightly to keep pressure on the tire. Reinstall the contact to the wheel. The oval hole in the contact should allow one arm of the contact to reach the metal tire. Reinstall the hub pressing it firmly into place so that the wheel won't wobble in the bearing. Test the wheel with the test wires you have set up, only this time put the contact of the light bulb on the hub instead of the bearing. Make adjustments as necessary until you have a good connection between the tire and hub. Now put the bearing back onto the hub and install the wheel back to the axle. The wheels need to be Quartered.
Quartering is a term used when one wheel is one-quarter turn off of the wheel on the opposite side off the axle. The two axles that don't have the drive rods connected to them can just be eyeballed. If you have to disassemble the drive axles with the rods connected to them than you may have to use a more scientific method for re-quartering them. North West Shortline makes a driver quartering tool for HO scale that may work. I have always had good luck eyeballing even the axles with the drive rods and testing to make sure there are no rough spots as the wheels turn. If I find a tight spot I will eyeball the wheels again and make adjustments until the wheels turn smoothly.
Test the locomotive on the straight and level track again. Reinstall the tender once you have the engine running smoothly, again refer to replacing the draw bar page by Kato for instructions. You can improve the tenders pick up ability just by adding a little weight you shouldn't need more than one or two ounces. For every ounce of weight that you add to the tender you can expect to lose about one car from the locomotives pulling ability.
We hope you find these tuning tips useful for getting the best out of this excellent model.