Lionel 6-81244 Pennsylvania M1A Legacy Smoke Unit Issues

I am not an expert on these things, Bob, but I had a Legacy PRR K4 steamer exhibit periodic smoking...and it turned out I over-filled it. In this case, I could hear it gurgling/spitting inside the main stack - so I let it sit overnight upside down and excess fluid drained out on a rag. Then, it worked again. This model has a separate fill for the whistle, so that was unaffected. I recall the M1a has one fill for both stack and whistle.

Bob, I have repaired some diesel smoke units that had the cube-cut wick contract/shrink.  it no longer touched the bottom of the smoke unit, so it was not in the fluid to wick it up to the heating element.

The heating element can also toast/burn the wick material so it becomes hard like a scab. the hard material will not wick smoke fluid and needs to be gently scraped off and new wick exposed to the heating element. 

I took the cube wick out of the smoke unit and pulled it gently higher like pulling on a buttermilk biscuit, expanding the height so it reached from bottom to the top heat element.

Good luck.

Sincerely, John Rowlen

First off, that smoke unit has the thermistor that may be out of position, and also the wick as John as mentioned above.  I had a similar issue with several newer Legacy locomotives, repositioning the thermistor and making sure the wick was good and in firm contact with both the resistor and the thermistor helps a bunch. 

If the thermistor is too far from the resistor, you'll get great smoke for a short time and then things go south.  If it's too close, it sounds like what you have.

Question:  Did it every smoke properly?

John Rowlen posted:

Bob, I have repaired some diesel smoke units that had the cube-cut wick contract/shrink.  it no longer touched the bottom of the smoke unit, so it was not in the fluid to wick it up to the heating element.

The heating element can also toast/burn the wick material so it becomes hard like a scab. the hard material will not wick smoke fluid and needs to be gently scraped off and new wick exposed to the heating element. 

I took the cube wick out of the smoke unit and pulled it gently higher like pulling on a buttermilk biscuit, expanding the height so it reached from bottom to the top heat element.

Good luck.

Sincerely, John Rowlen

Hi John,

Yeah, I figured at some point I'd have to open her up.  I was hoping that it was something simple because I really hate taking steam engines apart.  Thanks for the reply.

Chief Bob (Retired)

Paul Kallus posted:

I am not an expert on these things, Bob, but I had a Legacy PRR K4 steamer exhibit periodic smoking...and it turned out I over-filled it. In this case, I could hear it gurgling/spitting inside the main stack - so I let it sit overnight upside down and excess fluid drained out on a rag. Then, it worked again. This model has a separate fill for the whistle, so that was unaffected. I recall the M1a has one fill for both stack and whistle.

 

Paul,

This is the least invasive solution, so I’ll try it first.  However, I don’t hear any gurgling coming from the stack with the sound turned off.  Thanks for the reply.

Chief Bob (Retired)

gunrunnerjohn posted:

First off, that smoke unit has the thermistor that may be out of position, and also the wick as John as mentioned above.  I had a similar issue with several newer Legacy locomotives, repositioning the thermistor and making sure the wick was good and in firm contact with both the resistor and the thermistor helps a bunch. 

If the thermistor is too far from the resistor, you'll get great smoke for a short time and then things go south.  If it's too close, it sounds like what you have.

Question:  Did it every smoke properly?

Hey John,

Yes.  This condition just started recently.  This particular engine doesn't get a lot of run time so she has very low mileage and clock time.  Thanks for the reply.

Chief Bob (Retired)

Bob, 

I often forget that the smoke unit is like an old oil lamp in many ways.  It uses a consumable wick conducting smoke fluid that is set to smoldering by the heat element.  The wick will char/burn/toast over time.  The build up of the carbon "scab" as I call it, does not conduct smoke fluid.  In fact it blocks it from reaching the heat element. The carbon debris needs to be removed from the wick and the heat element.  Then the clean wick material is stretched and moved up against the heating element again. 

The only parts Lionel would service are the heating element, the fan motor, and any board controlling them.  The cleaning of the wick is our maintenance responsibility or whoever we pay to do it.  Once it is newly clean, smoke will pour from the smoke stack.  See the pictures of my Erie PA units. Gunrunner John commented that it was too much smoke like real engines needing service.  Over a short time, the smoke returned to a normal level.

You can see the fan duct work is half way up from the bottom of the reservoir. It would take a good amount of fluid to block the opening.

Wait for Gunrunner John to answer any other questions.  I was forced into servicing them because the engines did not smoke well, and I bought them on Ebay without a warranty from Charles from Nicholas Smith.

My very first train set was the Erie PA AA Freight with four freight cars that my Dad put on a board under my crib. I am now 69 years old, and the train is on my shelf.

Sincerely, John Rowlen

I have the M1a and it smokes like crazy.  I will say it takes more smoke fluid than some of my other Legacy engines.

You say it gets very little run time.  Are you sure its just not too dry.  I find I have to put at least 20 drops in mine.

Everyone always jumps to the overfilling thery, but on any engines where I found it was not smoking enough, when I open them up the wick is basically bone dry, even though I put in the recommended amount.

That would make sense why it smokes at beginning and dies off.  If you open it up, let us know if the wick is bone dry.  The wicks will always have some charring eventually but can still produce plenty of smoke if kept saturated enough.

PUFFRBELLY posted:

gunrunnerjohn posted:

Question:  Did it every smoke properly?

Hey John,

Yes.  This condition just started recently.  This particular engine doesn't get a lot of run time so she has very low mileage and clock time.  Thanks for the reply.

Chief Bob (Retired)

Probably time to open it up and carefully replace the wick.  I get better results than the factory pad with the Lionel braided wick.  Make sure you don't disturb the position of the resistor or thermistor and just fill the bottom cavity with the shredded wick.  Make sure it's firmly in contact with the resistor and thermistor but do NOT totally bury them in the wick, the resistor has to have airflow across it to move the vapor to the stack.  Of course, make sure you haven't blocked the flow of air from the fan chamber across the resistor to the stack...

SandJam posted:

I have the M1a and it smokes like crazy.  I will say it takes more smoke fluid than some of my other Legacy engines.

You say it gets very little run time.  Are you sure its just not too dry.  I find I have to put at least 20 drops in mine.

Everyone always jumps to the overfilling thery, but on any engines where I found it was not smoking enough, when I open them up the wick is basically bone dry, even though I put in the recommended amount.

That would make sense why it smokes at beginning and dies off.  If you open it up, let us know if the wick is bone dry.  The wicks will always have some charring eventually but can still produce plenty of smoke if kept saturated enough.

You may remember the posting about filling smoke units by Laidoffsick some time in the past.  His fairly exhaustive analysis was that 20 drops is typically not nearly enough for a dry smoke unit.  His fill was in the 40-60 range for a totally dry unit.

Greetings Everyone,

 First, thanks to everyone who took the time to respond and offer solutions.  Now, here’s what I did.  After separating the shell from the drive mechanism, (much easier that I thought it would be), I removed the smoke unit, (it’s a 2-chamber unit with 2 fans and, in my opinion, rather large).  Once removed from the shell (2 small screws), I was able to remove the smoke element PCB and access the “wick”.  In this case the “wick” was basically a square chunk of a felt-like material and yes, it had quite a bit of carbonizing around the wick and both resistors.  I carefully remover the “wick” using an X-Acto knife with a brand-new blade and gingerly cleaned the carbon off of both resistors as well.  I then replaced the crappy factory “wick” with the standard Lionel 8” long pre-cut fiberglass “batting”.  I used one each on each side of the divider which is inside the area that contains the wick material.  Before I buttoned-up the smoke unit, I “primed” both wicks with approximately 20 drops of JT Mega Steam Coal Fired scent smoke fluid.

 At this time, I re-assembled the locomotive and it was off to the layout to see if my efforts were successful in correcting the problem.  BINGO!  That’s all she wrote.  My Pennsylvania Railroad M1A now smokes like I think she should! 

Now for a few observations.  The Whistle Smoke Hose that connects the smoke unit to the whistle was a little loose.  Rather than re-use it I decided to replace it.  I found that standard airline tubing purchased at the local aquarium store worked perfect.  It’s just a hair smaller but it fits nice and tight.  The name of the product is Lee’s Aquarium & Pet Products Airline Tubing, Catalog Number 14505.  The smallest available was 8’ but for 3 bucks + sales tax it was a bargain compared to Lionel’s price of $1.50 + Shipping for an approximately 6” piece of tubing and if I have to rebuild the smoke unit in the future, (which I’m pretty sure I’ll have to), I’ll have the tubing in hand.

 Second, the 20-drop smoke fluid rule.  There is no way that 20 drops of smoke fluid will begin to completely saturate both wicks in this smoke unit.  Like I stated previously. This is a large (IMO) smoke unit.  That being said, after I “primed” the smoke unit and re-assembled the locomotive I added 20 more drops after she took her place on the layout.  I did this earlier this evening and I’ll see how she smokes after the fluid has a chance to saturate both wicks.

 Again, a big thanks to everyone that took interest in my dilemma and who also took the time to offer solutions.

 Chief Bob (Retired )

Great you got it working!  

So the question is, if you had put in more smoke fluid, would it have worked without opening it up?  My point being if a engine has not been run in a long time the wicks dry out and just needs a good soaking.  All wicks will always have charring.  That's the nature of the design of these units.  Some charring does not negate great smoke output unless its totally 100% burnt.  So my point is that a lot of people open up engines and may not have to if they just re-saturate their wicks if an engine hasn't been run.  Because if you think about it, it smoked fine the previous time you ran it, it sat and then it didn't, so its not like the wick got 100% burnt sitting on the shelf.  The reason I say that is because if I have that issue I usually give the unit double the amount and let it soak and it always works.  I haven't had to open any engines to fix smoke output.  I opened an engine once a few years ago because I thought it was the burnt wick, and found out after all the drops I had put in, it was still bone dry and that's how I figured out what was going on.

Well, opening it was a good idea to get rid of the lame factory pad.  I'm convinced they use those because it's dirt simple to toss them in during assembly, the shredded wick takes a little more work.

I smiled when I saw the observation about the 20 drops being insufficient, I've observed that in the many smoke units I rebuild.  When I have one apart, I try to soak the wick before assembly, and I can assure you it uses more than 20 drops.  For a standard Lionel or MTH smoke unit, I use about 2/3 of the Megasteam dropper, that is around 40 drops.  With that much fluid in the bowl, you can pick the wick out and it's all in the wick, so it's hardly too much.

Glad you got it working good, Bob.

Hopefully I can learn more about these smoke units when I visit GunrunnerJohn in the near future

I also suspected that 20-drops of fluid wasn't enough...I did overfill one Legacy steam though with 20-25 drops, but maybe it had an obstruction that prevented saturating.