new MTH PS3 Big boy 2 rail loses chuff?

Check continuity on the right (?) side drivers for continuity with each other. I believe the right side drivers pick up power on two rail locos.  Not all the wheels pick up power, but I would guess 3 or 4 drive wheels.  The drivers pick up power through the axle with a spring under a screw.  There was a problem with the temper of the spring losing tension on some locos, so if their is lack of continuity, I would check them.  The paint on the drive wheels between the rim and axle can pose problems, so check continuity between the rim and axle.

On the tender, the opposite side wheels should have continuity.  There were also quite a few problems with the 2/3 rail switch.

With the drawbar, repeated connection/disconnecting can cause the pin receptacles in the tender to lose their grip on the pins.  Swapping the harness end for end in the tender is a quick fix, otherwise I take the harness apart and tighten the clamp on the receptacles.  I like to remove both shells, connect everything, and check continuity from one end to the other, noting that there is a resistor in one lead in the tender harness.

Luckily, the big boy is easy to open.  4 screws and the boiler clip.  Dig into it.

None of that is why it runs but misses a chuff is it?  For PS-3 you have the data signal back and forth between engine and tender.  IF PS-3 doesn't see a tach signal it moves without speed control, will stop, then move again without speed control.  Is the motion good just no chuff?

Possible the 5v draw from smoke fan motors is creating noise and the tach reader misses.  How is it with all smoke off?  All the obvious tach reader checks, but also replace it.  It has circuitry on it so it could have issues.  Then drawbar especially 5V, data, DC ground line continuity.  Though with everything else working fine why a chuff miss only seems to point other places not draw bar.  G

When it misses its chuff, it continues running smoothly. It chuffs much better with the smoke off. I still heard some missing chuffs here and there.

I did notice a problem later on where the whistle wouldn't react to commands. I cycled it between playable and regular and it would return for a moment or two and then lose control of the whistle again.

Whatever it is, it's getting much worse. I don't disconnect the tether. It's only been apart maybe twice. On the very first run, I noticed an issue with it not fully connected. So I added a piece of hose. It appears to be fully seated right now.

It seems to me like the engine is losing signal between the boiler and the tender for some reason. It seems to be a power hungry engine and that's why I swapped out the power supply. So I'm thinking there's more there.

OK, first thing. I get no continuity between any main drivers on the right side of the engine. I checked at the tires and the rims.

I got various readings on the left side around 4 or 5 ohms.

I looked at the manual for removing the body. It, of course, skips over that!

It does have one pic that shows 4 screws. I'll have to guess at it because I can't even see the screws in the picture. Ah, the fun of getting old.

2 screws under the trailing truck, 2 screws on the center steamchest, a “L” shaped hook retains the swiveling front drive assembly and a plug from the boiler.

Thank you Jon. I figured it out because of the same mounts on my one gauge challengers that I've serviced. So easy.

It appears that only the front two axle on the front drivers, and the rear two axles on the rear main drivers pick up power on the right side?

I got frustrated that I couldn't get a reading on the drivers. I touched the probes together and got a reading. I touched both to the very same tire and got nothing?

I had to scratch them to get a reading. So I am wondering if there's some coating on them? What material are they made of?

I stretched out the front most driver's pick-up spring and now get a reading between the front two drivers. I do get a reading between the rear two as is. I had to scratch the surface with the probes.

I guess I will start forward with some type of main driver tire cleaning.

I had to add wipers to my MTH Alleghenies that I converted. That helped them run thru switches with dead frogs better. This engine runs right thru the same switches. I have a feeling there's an issue there causing the chuff problem? (and maybe poor signal to the whistle?)

I see that MTH put wipers on the trailing truck.

I'll have to center my focus once I learn if it's just a boiler board problem or a whole engine issue. Using GGG's post confuses me on where to look.

I see that the tender seems to pick-up power on the left side tires. So that leaves me to wonder if all the right side is from the engine only?

Maybe I should add wipers to the right side wheels of the tender????

Well, so far so good. I cleaned all the wheels and the chuff was perfect so far. I don't have the smoke on yet because it bothers people here. I'll test it further tomorrow.

The whistle was better yet still not perfect. It seemed to work when it wanted to. I'll run signal tests with and without smoke tomorrow.

I have a feeling she needs one more power pick-up point. At least she runs good. I may look at improving the stock speaker as well. I'm not crazy about the sound quality. Looks like the stock speaker is on a stand in the tender with a baffle on the back. I couldn't get a good look at it yet.

Maybe I can cram a JBL in there.

FWIW, I am not at all impressed with the MTH Premier PS/3 Big Boy sounds.  The whistle sounds like a wounded cow to me.  However, mine doesn't have any issue skipping chuffs.

I won't argue with you Sir.

I did say the other brand sounded like a donkey and that post got deleted in short order!

@Engineer-Joe posted:

I won't argue with you Sir.

I did say the other brand sounded like a donkey and that post got deleted in short order!

What.......

@Engineer-Joe posted:

I won't argue with you Sir.

I did say the other brand sounded like a donkey and that post got deleted in short order!

Well, that was "Fake News".   At least for the Vision Line Big Boy, the sound was what sold me on it when I saw it at York!

No fake. Diesel horn. Really sounded sick. Maybe like a wounded cow?

@Engineer-Joe posted:

Thank you Jon. I figured it out because of the same mounts on my one gauge challengers that I've serviced. So easy.

It appears that only the front two axle on the front drivers, and the rear two axles on the rear main drivers pick up power on the right side?

The drivers that pick up power have a screw with a wire lead attached to it directly over the axle on one side of the frame.  It’s hard to see in your pictures.

As for the speaker, I’ve installed the cardboard tube used on some PS1 locos in the  space under the speaker, allowing space for the harness to pass through, to marginally improve the sound.