Earlier this year I picked up a used Kato 2-8-2, probably a second run, from my local hobby store. The engine came with a decoder preinstalled (cool!). However, performance has been iffy; the required a large amount of breaking in before it could even try to run decently on DC power, and on DCC it would hardly move at all. Fast forward to now; I've pulled it back out of the box after a few months in storage. Now, if I place it on the track and turn on power, I might get the headlight, and sounds indicating there is power flowing to the motor, but no movement. I've checked and cleaned the track; my other engines run just fine on it. If I place the engine on my Woodland Scenics "Tidy Track" wheel cleaner and allow the wheels to slip (the engine is up against the end), everything works just fine. I'm assuming the issue here is lubrication; either the motor or the gears are acting up. However, these symptoms are similar to those with my first-run GS-4, where people have suggested the issue is cracked axles, a common malady with those engines. Is it possible the Mike has the same problem, or does it just need some oil?
Doesn't need oil. You probably have a first run, with the original drivers. These have notoriously bad pickup, which wreaks havoc with DCC. If you can, try adding some weight in the tender. This will provide better pickup from those wheels. See if that helps (an easy way to check is put some weight on the top of the tender, first). Since you are using the wheel cleaner, I assume the drivers are clean (check the tender wheels, too). Kato no longer has replacement drivers available. You can check on eBay
One of the weak links on the Kato pickup is the two phosphor-bronze wires hitting the split drawbar pin under the cab. It 'looks like' a good idea, but it really isn't. If there is any oxidation at all on those wires, or the drawbar pin, your performance will be all over. On one that's been sitting around a while, oxidation everywhere is suspect. So when you're cleaning, check that too - clean, tighten up the wires by bending them if necessary. On mine, I finally hardwired the tender to the split locomotive frame and that solved that.
One universal problem I've seen on current-production N steam is that spring-loaded split drawbar - with two spring wires hitting a split pin on one or both ends of the system. The connection area is absolutely miniscule, it tends to accumulate mild carbonization, and the connection is also always in motion which changes the area of contact from a 'clean spot' to a 'dirty spot' in seconds on curves, humps, etc. No matter how many wheels you've got, it's still piping through that design. At least the end-axles tend to self-polish. The drawbar should, and with enough running actually will, but if it sits a while, all bets are off. Hard-wiring the tender isn't a whole lot better, because it seems like no matter what you do, the movement of the tender will eventually fracture the wires. So I design mine with 00-90 tapped screws on both ends and very soft stranded wire - into the frames where I can find a spot, anticipating the inevitable. I've resigned myself to having really, really reliable tender pickup until the moment I don't, and then workbench it to replace or repair a wire. I've done this on just about every steam locomotive I own with tender pickup, reluctantly, but decided its still the best way for reliability. Everybody checks the wheels, some check end-axles, but these drawbars are just as bad as a unit ages.
IMG_1863 by SVRailroader posted Sep 1, 2017 at 8:22 PM IMG_1861 by SVRailroader posted Sep 1, 2017 at 8:22 PM Thanks for the tips, folks. Above are two photos of the engine in question. The previous owner added a backup light (hence the partly-removed shell) and a metal oil bunker to provide weight; I suspect the decoder prevents easy addition of more weight within the tender. There are also four wires running from the engine to the tender, which probably were added with DCC; I'm guessing two are motor and two are headlight, but I wonder if any could be pickup? Regardless, I also noticed this about the initial run, from Spookshow: "As it turns out, there simply isn't enough metal on the back sides of those drivers to provide reliable conductivity (vis'a'vis the wipers)." Would it be possible, or practical, to "add metal" and improve conductivity? Or would a whole new driver set be a better idea? Thanks
If there are only 4 wires, then the installer is probably using the contact strips in the tender for power pickup. Since it is open, where do the red and black wires go? If the pickup is in the tender, the drawbar issues will be more pronounced. As said above, the revised drivers are better, but difficult to find.
The red and black wires go to the rear truck, and connect to the contact strips in the tender. Those are hidden beneath a weight and cover, and I haven't tried to disassemble that yet to get a better look.
OK - that confirms the install is using only the tender contacts for the power pickup. Any track power from the drivers has to go through the drawbar wires. As designed, the tender pickups are supposed to supplement the drivers, not the reverse. Running two additional wires from the loco to the tender may be useful.
I had one of the first runs that I got back when they were first released kept it on the shelf until 2004. Got my layout going that year only to find out the thing would not run, but I could hear the motor and knew it was getting power. Upon disassembly (Not for the weak at hart) found it had a striped gear, looked at the instruction sheet that came with it located the part number of the gear, and ordered a replacement. You may have a bad gear as well?
I thought phosphor-bronze oxide was conductive unlike brass oxide. Maybe the wipers are not phosphor bronze?
I ruined one of these trying to get it to DCC and sound. I like the Model Power one better. I'd rather add details on the Model Power 2-8-2 and have it haul a crap ton of cars than the Kato Mikado.
I don't think the problem is a stripped gear; as I said, if I can hold the engine in place, everything works just fine. If I jiggle the tender even a tiny bit, though, it stops. So probably a conductive problem. From what I can see, these do appear to be phosphor-bronze oxide. They probably need to be cleaned, or as suggested, replaced with hardwiring.
I have done well over 100 DCC sound installs on this type of locomotive. The Drivers are a problem on the first run units and I have not found a way to repair that other than replacing the drivers with the revised drivers. Which is no longer serviced from Kato- So look for a second run unit and swap shells or drivers. As for the draw bar contacts. Lube & clean using NeverStall. Or has I do when doing a DCC install I run 5 wires for the install. 2 track power, 2 motor and 1 for the front headlight. I run these back to the decoder in the tender with very fine flexable wire ( From ESU Lok Sound ).
You can use a nickel or silver-based conductive epoxy on the backs of the Mikado drivers, right at the points where the bronze strips touch near the wheel rim and also near the center hub where they also lose contact. I have done it with MG Chemicals Nickel Print and also with a Circuit Scribe conductive ink pen (uses silver) https://shop.circuitscribe.com/collections/new-products/products/circuit-scribe-conductive-ink-pen The silver pen works better. Silver is more conductive than nickel and the thinner pen ink seems to flow better. They don't sell it in a bottle, so you have to put up with dabbing the point of the pen into the joint until you build up a little puddle of conductive ink between the bronze strip and the rim. Sometimes it takes patience and you have to scratch it off with an Xacto and try again, but it works. Check between the phosphor bronze strip and the wheel rim with an ohmmeter. With Nickel print, you can get down to a few ohms of resistance. With the silver pen, I could usually get under a few tenths of an ohm. Either way, the drivers will work. If you test them all with an ohmmeter before you start, you'll know which ones are the bad ones so you only have to fix those. They will have "infinite" resistance. As for the drawbar wires, yes the wires themselves are phorphor bronze and as such, they tend to stay cleaner and more conductive when they oxidize than, say, brass. But the split pin location on the frame under the cab is NOT phosphor bronze and requires cleaning. It's best if you clean it with VERY fine sandpaper, like 800 grit, and then follow up with more like 2000 grit (you can get this at any auto parts store). You want to *polish* the surface, not just scratch the corrosion off. If you leave the surface rough, it will oxidize and collect dirt even faster the next time. Shoot for as much like a "mirror" finish as you can polish on it with super-fine sandpaper.
I did eventually purchase one of those silver conductive pens, and it did indeed seem to improve conductivity. Unfortunately, when I placed the engine on the track, it was dead. Both DC and DCC. My test track couldn’t even register the decoder to begin with, just an open circuit. Therefore, I think the likely answer is that the decoder burned out last time I ran it (which was quite a while ago). It was an old decoder, from the looks of it; I couldn’t ID the make, and it had a green lighting wire instead of blue. So I guess I should look into getting another one. Additionally, if I commit to that, I may try rewriting it to work on DC before adding a decoder again, just to suss out any other issues.
Bummer! Sorry for your bad luck with the Mike. I am really cautious about buying second hand. I usually have a donor on hand in case the "new" unit has issues.
