Mth premier triplex smoke unit servicing

Please keep us posted. I have this engine and I like to be prepared if there are issues (fingers crossed!).

Don

I had to take mine apart right after I got it because the front smoke unit and stack were misaligned, resulting in smoke coming out from underneath the boiler. I do not remember having to take off any of the main running gear to get inside the boiler shell, but I do remember having to detach the tender drive train from the engine. There was a link between them at the rear of the cab. Maybe this is what you are referring to, but in any case I found a diagram - which might have been in the manual - showing the body mount screws’ locations. Overall it was not a long job but certainly required a foam cradle to hold the engine in place upside down while I was detaching the screws.

The rear smoke unit is not that hard to get to. As you are refilling it through the hole in which the rear stack is seated, there’s a possibility of it getting clogged or a film forming from smoke fluid. I always shoot a little compressed air down mine to clear away any residue.

That rear smoke unit is the only MTH smoke unit I have ever had that failed and had to be replaced. I don’t know why it  failed as the tech guy I took it to for repair, after I could not diagnose the fault myself, just told me that sometimes stuff happens!

Hancock,

We’re you able to remove the front  smoke unit or just repositioned it?

@Hump Yard Mike posted:

Hancock,

We’re you able to remove the front  smoke unit or just repositioned it?

I think that I had to detach it from the chassis to re-align it. Anyway it was a standard MTH unit and although I did not have to take it apart, the PCB on top was held on by screws and could have been removed to replace the wadding.

The reason for the back smoke unit clogging is MTH made the output hole very small and when you put smoke fluid in or smoke is coming out bubbles form.

@Hump Yard Mike posted:

After it was put back together and running it for a bit, it looks the  front smoke motor may be bad as the smoke out put is weak on individual chuffs, but good when on constantly like when stopped.  It also seems to occasionally stop smoke output a times intermittently when running fast enough that there no distinctive individual puffs.

The most likely reason for this behavior is a loose impeller on the motor. The MTH dynamic braking is hard on the friction fit and if the impeller fit is loose, the motor "leaves it in the dust" and then stops before the impeller gets moving.   When you stop, it runs continuously at low speed, then the impeller catches up and works. It's very unlikely it's the motor. You can either use a new impeller or put a drop of CA adhesive on the inside of it and shove it back on. Once it's dried, it should be good for at least a spell, the 100% cure is a new impeller.

thanks John, I will give it try