Motor in my Minitrix K4 may be starting to go

I purchased Kato’s N Scale Broaway Limited set to run behind my Minitrix K4 and I’ve noticed the engine is behaving strangly. It struggles and stalls out at lower speeds on the straightaways by takes off like a jackrabbit though the curves. I replaced the stock tender trucks with Bachmann all-wheel pickup tender trucks. So I eliminated power pickup as the problem. I also tried cleaning the wheels, cleaning the track and lubrication, none of which helped. The drivers also appear to be properly quartered. I’ve also noticed the problem seems to get worse the longer the engine runs.

Do you guys have any ideas? Ay help is much appreciated.

the train could be too much for the K4, are you doing the basic 10 car set? also how tight are your curves, I had a bachmann Northern that couldn’t really move 6 heavyweights around an 11.25 without slipping. do you have traction tires on any of the wheels?

yes I am running the 10-car set. Two of the six drivers are equipped with traction tires.

Gary,

It appears,that the OP,is not having any problems,with the engine,going around curves…

Cheers,

Frank

It sounds like a electrical problem which is improved when a side force, from the curves is present.

Does it have a light and if so does it stay on steady when the engine is struggling and stalling?

The engine does have a light but it only comes on when the throttle is wide open. When the engine stalls, I can hear the motor humming.

at least, I put some thoughts up there using a similar experience I had with one of my steamers.

anywho, could there be something metal on the loco frame touching something else and causing the current to disappear on straightaway’s?

GP-9:

My suggestion is that something is binding when the locomotive is going in a straight line. I don’t think it is a power pick up problem because it is receiving enough power to make the motor hum under load - an unpowered locomotive will not hum. Plus, you have taken steps to improve pick up.

The first thing I would do is test the locomotive with another train of similar size. If the problem persists you will know that the cars are not at fault. You could also put a different engine on the train to see if it has the same problem. If not, then the problem lies within the K4.

If it is the engine, then finding the problem might take some work. I would start by disassembling the engine to the point where you can turn the drivers individually by hand. Then gently turn them and apply sideways pressure to see if you can feel resistance at any point. If there is no change in resistance then that suggests a look at the rods and cylinders. Put them back on and turn the wheels, again applying pressure from side to side. Since the apparent binding is significant enough to stall the engine, when it happens it should be noticeable.

When you have the engine apart, I would suggest using a magnifying glass to check for any burrs or scoring. Remember to check the power pick ups for binding. Even though they appear to be delivering power they could still be the cause of the binding. Check the gears for flash and debris too.

Please let us know what you find.

Dave

After it stalls / hums, what happens when you reverse the engine? How do you get it to run at this point?

How many feeders are going to the track from the power pack? Sounds like loose rail joiners.

Pete.

P.S. Look at the last post of your scratch building thread. A TKM with a kitbashed H6Sb in N scale.

I did exactly what you said. I removed the motor and tried rotating the drivers and found a very bad bind. From there I removed the drivers and examined each gear. There were a few pieces of loose ballast suck in them. I reassembled the the locomotive, put it on the tracks and its running smoothly. It doesn’t explain why it ran through cuvres better, but it’s runn

GP_9,

The curve issue,may have caused the drivers to move laterally just enough to miss,the junk on the gears…

In any event,Glad You solved Your Problem,

Cheers,

Frank

GP_9:

AH! Great minds think alike!

Glad you solved your problem. Sorry if I stated the obvious.

Dave