Trouble with MTH F-7 Smoke units...Please Help!

[n1vets333]

I just recieved my MTH Premier F-7 ABA engines yesterday that I bought off ebay. The train looks as though it was hardly run if ever. The rear smoke unit smokes well but the front unit doesn't produce3 smoke the way it should. Only when switching from nuetral to forward or reverse do I get a quick puff of smoke. This is telling me that the heat element seams to be working at the fan for atleast that second. I read in an older thread that sometimes if fluid gets on the fan it could cause the impeller to slip. Does this sound like the problem? Did anyone else ever encounter this same issue? If so how to correct it? I love smoke and that is one of the main reasons I choose MTH over Lionel for the f-7's so I would really like to get them working properly. By the way I am running the train in conventional mode only as I have yet to acquire a DCS controller. PLEASE HELP!!!!!!!

[phillyreading]

Take the top off the F7 in question and look at the smoke unit to see if your fan might be slipping or you need to push the miniture connector into place better. If it is a PS-2 unit you may need a new battery for the memory to work properly.

Lee F.

[n1vets333]

I am going to take the body off today and diagnose the engine but why would the battery cause the smoke not to work? Does it have a say in the smoke unit? The sounds and everything else work as they should.

[Anonymous]

A dead/weak battery won't affect smoke output.  It sounds like the wick is burnt where it contacts the heating elements.  This would cause the symptoms you described.  Go to Wal Mart and buy wicks for a Tiki torch.  Take the shell off the engine and remove the screws (usually four) from the top of the smoke unit.  Pull the cover off, being carefully as to not destroy the gasket.  To remove the wick, first apply some smoke fluid to the point where the wick contacts the elements.  Gently spread the heating elements apart far enough to pull the wick out.  To spread the elements, place one thumb on one element lead and the other thumb on the other lead, then gently press. Do NOT apply pressure directly to an element, they break easily.  Cut the Tiki wick open and remove enough strands so that this new wick is the same thickness as the one you removed.  Cut to the same length if necessary.  Fold the new wick in half, twist the bent end once, the put it between the elemts and squeeze them gently back together.  Reassemble the unit, then add 30 drops of fluid.  Make sure the wick doesn't obstruct the air passage. Give the fluid an hour to be sure it has soaked the wick and test the locomotive.

[n1vets333]

Thank you for the detailed response, I will be sure to use this thread as a guide during my diagnostic of the unit.

[SRen]

Another possibility is that the DC fan motor that is suppossed to blow the smoke out of the stack is wired backward.  This will cause the smoke to be sucked back into the locomotive, the momentary puffs you get may be caused by the fan momentarly stopping allowing the vapor to escape on its own.  A gentleman named Jim Barrett addresses this exact problem on a DVD called Backshop Volume 11 for sale by OGR publishing.  Simply Google OGR publishing to find their Web site.  Hope this helps....

 

Scott