I have a RK GP-9, 30-2601-1 that has a 3V battery. It's listed in the 2005 Volume II Catalog.

It always seemed that the smoke output was ‘flaky’ and would vary from no smoke to plumes of smoke.

Yesterday I reviewed all the available documentation and the recent postings on the OGR Forum. Then I opened up the Smoke Unit to check the wick out. It was a bit charred and I replaced it with new wick material I had on-hand (from a wine bottle lamp kit). With the shell still off I loaded it up with ~20 drops of fluid, let it soak for a few minutes, and it smoked like crazy. But, after replacing the shell and letting the engine sit overnight, the smoke output eventually went back to being ‘flaky’ again. Adding more fluid only yielded a brief period of decent smoke output.

I know there are control settings & features that affect smoke output:
- SMOKE on/off button
- LABOR/REV UP &/ DRIFT/REV DN rocker switch
- MENU/SOUND/PROTO-CHUFF & CHUFF RATE
- MENU/CONTROL/SMOKE VOLUME & LABORED SMOKE

I’ve tried various settings of these controls in the past and it appears that the only way to get a decent volume of smoke all the time is to:
- Either, press the LABOR/REV UP a number of times - which yields higher rev sounds [and automatically overrides the Proto-Chuff feature].
- Or, set the CHUFF RATE to about 5/6 or higher - which yields higher rev sounds but does not override the Proto-Chuff feature [even though the rev sounds do not seem to vary with engine speed].

I would appreciate your experience and comments to confirm that I am on the right track and to verify that I can have either decent smoke output or varying rev sounds (Proto-Chuff) but not both?

Many Thanks,

Tom

Tom,

I own a pair of GP9's, an older Premier, and a newer Rail King Scale that is most likely a twin to yours. They are both prodigious smokers, however, they also share a common design "feature".

On many diesels the smokestack lines up directly over the smoke unit intake hole. Unfortunately, neither one of the GP9's two smokestacks do so. Instead, there's a ramp under each hole that routes the fluid to the smoke unit which is between them. Often, the smoke path will get jammed with an air bubble, smoke fluid or lord knows what and the engine will just stop smoking.

In this case, try blowing gently down each smokestack, while holding your finger over the other, to clear the obstruction. That generally works for me.

I have a couple of GP-9's and mine smoke very well. I always suggest to improve the smoke flow open the smoke unit and you will see that on the resevoir there is a small opening for the fan to push air through. I only use MTH wicks and twist two wicks together and I make sure the wick material does not block this hole. I put the wick material to the side where the hole is free to get the air through.

Barry,

Thanks for the tips to clear the "stacks". I did try this without any change.

Paul,

I saw the offset opening between the fan and reservoir which allows fan air to pass over the heating resistors (and out the stacks). I pressed the replacement wicks below this opening and will try placing it over to the wider side to avoid blockage.

============

NEW OBSERVATIONS
The more I sit and play with this the more I suspect the fan impeller may be loose and not turning.

Here's why:
- When I toggle key #1 to turn the smoke from off to on there is a small puff of smoke and then nothing.
- The fan/motor noise is a bit more pronounced than on other engines.
- When I do have smoke with the engine stopped smoke leaves the stacks in a lazy column (versus a more forced air appearance). This was most apparent when the shell was still off.
- Also when the train is moving the smoke just trails behind the stacks (and does not appear to be forced out by the fan).
- My earlier descriptions still don't seem to hold true. (i. e. - sometimes it smokes and sometimes not - no matter what the settings are).

I did some more searching for fan/impeller problems and found a July 05, 2009 thread about loose impellers where Marty Fitzhenry suggests a test and a fix repeated here:

TEST
".... I have run into this many times and what you have is the fan impeller slipping on the motor shaft. I would like you to do the following if you would.
Take the top off the smoke unit and with two wire leads connected to a 9V battery, touch the connections on the bottom of the motor. If it spins ok, please go to this next step. Next pull the impeller out of the well and off the shaft. Use small needle nose pliers. It is a pressed fit and will pull straight up. It is very common for these to spin on the motor shaft. ...."

FIX
".... Next you can purchase a new impeller or do the Mickey Mouse fix that also works. That is as follows. Clean the impeller inside and take a pair of small side cutting pliers and gently nick the motor shaft in many locations. This has to be done very gently so not to cut into the shaft or bend it. Now press the impeller back on and assemble your locomotive. Please keep us posted. Do this and do not use glue or anything else. ...."

I'm going to open the engine back up and see if impeller 'stalling' is the cause of the problem. If so, I'll see if I can do the Mickey Mouse fix - or get a smoke unit replacement if the fix doesn't work.

Tom

The slipping fan impeller was going to be my guess. It fits the symptoms you described.

UPDATE
------
Took the shell off and placed the engine on the layout track to run the smoke unit thru it's paces.

Fortunately I could see that the fan was spinning on & off when I cycled the smoke unit on & off from the remote. But there was only a wisp of air coming out.

So, following Paul's advice, I carefully lifted the top off and checked out how the wick was positioned. And, as Paul said, I found that the wick was blocking the opening between the fan and reservoir. I went back to the original (three) MTH wicks and made sure the wick material did not block the opening by putting the wick material to the reservoir's wide side by the opening.

This seems to have done the trick!

I ran the smoke unit without the shell for some time and while I was waiting:
- I took out the 'ramp' Barry described to make sure it was clean and clear and it was AOK.
- I also measured the voltage to the heat resistors just to verify my earlier guess about when smoke output is highest. I found that the voltage (and smoke) was highest when the revs are maxed out using the LABOR/REV UP or CHUFF RATE controls.
- Lastly, since the fan and resistors are in use all the time (to simulate a diesel engine), I found that the smoke fluid is used up a lot quicker than that of the intermittent chuffing/puffing steam engines.

So, I'm happy to report I'm back in business after I put the shell back on and now the smoke billows out of both stacks.

From now on I will add ten or more drops of fluid before turning on the smoke.
And, I'll pick up some spare MTH wicks to fix smoking problems when the wicks are dried out and charred.

Here's a short clip showing the engine smoking away:

VIDEO

Thanks to all for your help and guidance....

Tom

quote:

From now on I will add ten or more drops of fluid before turning on the smoke.

May want to consider adding the smoke fluid 'after' you run the trains for the day. Be all set the next time you run as will absorb during the night. I use even more smoke fluid (almost a full megasteam glass dropper) and have had no problems with any of our MTH engines with adding too much.

Smoke is a beautiful thing.

Tom glad to see that the smoke unit is fine and it was just the wick blocking the hole that caused the problem. That is common that sometimes when assembled in China they don't get the wick material lined up right. If you have any MTH engine and it isn't putting out a ton of smoke check the wick and it's positioning and I think you will find if you make sure the wick isn't blocking the opening it will smoke you out. When folks use wick material like tiki torch material while it may work it doesn't work as well as the wicks designed for the smoke unit. The wick only needs to get the fluid up to the heating element, it doesn't have to fill the entire smoke resevoir. Too much wick is just as bad as not positioned right.

I have an Alco S2 that smokes 'lazily'. I will have to remove the shell and check the wicking. Thanks for the info, good thread.

George,
Thanks for the tip to fill 'after'. I've tried both ways but never added more than a few drops. I thought the fluid would evaporate if left standing for awhile. I'll go for the full dropper of fluid 'after' and give the wick time to soak.

Paul,
The MTH wick fiber was much stiffer/coarser than the fine fiber in the wine bottle lamp wick I used. This might have caused the blockage because it wouldn't stay put. I'll pick up that MTH wick with my next Order or at the next Train Show.

pennsydave,
Dressing the wick away from the opening is a bit hit and miss as it can move when you replace the top of the smoke unit. After assembly I used a toothpick through the top stack to push the wick to the side and keep the opening clear.

Thanks again for all the tips,

Tom

Push the coils apart when putting the wick material in and then squeezr them back to hold the wick material in and it won't move so easily.

Hey guys

First I would like to second Paul's statement on the wicking.

I don't know exactly what the MTH stuff is made from but it does seem to be almost like a fiberglass type of material and probably has a high burn rate.

Torch wicking is meant to burn and is typically of some type of cotton, hence I wouldn't run anything other then the MTH wicking material.

This stuff is pretty cheap, a dollar a wick in a three wick pack I belive.

Give Midge a call at (410) 381-2580 Ext 516 and you'll have it in the mail box in a few days.

Second, a little tip I fine helps me with installing the whole assembly is to put a little bit of fluid in the res before you try to pack everything in, as you are installing the wicking part it will soak this up and will make the material much smaller and streamline and much easer to work with.

Give it a try.

Pennsydave

My MTH Alco S2 is also a lazy smoker.
I did take mine apart (not an easy job) and repacked the smoke unit.
Not much change.

Of all my MTH engines, this is the one that requires a blow down the stack a few times at the beginning of each running session.

Once she's "primed", warmed up, the smoke output remains steady.
Despite this little flaw, it remains one of my favourites. Great sounds!

I never cared for the "twist around the smoke element" with the wicking.
I've used fiberglass (from your attic) insulation in MTH, Lionel and Postwar (where I changed the wire resistor to element) and have never had an issue.

Regards
Dave

Dave, Thanks for the info on getting the shell off. I too have to blow down the stack sometimes to get the smoke going. But it is a great little engine. I don't have a large layout so small is great for me. There won't be any Challengers or Big Boys on my layout, not even an E8 which I would love.

quote:

Originally posted by VaGolfer1950:
Push the coils apart when putting the wick material in and then squeeze them back to hold the wick material in and it won't move so easily.

Paul,

Again - right on - Thanks.

I found the coils pinched midway along the length of the wicks and the wicks were at the far end of the coils away from the opening.
Because I ran the unit too 'dry' the wicks were a bit charred where these contacted the coils. This time around I tied all the wicks in a knot around both coils at the far end. This arrangement kept the wicks in place and gave me lots of contact with uncharred parts of the wicks.

WBFLine,

I agree that MTH wicks are best material - just the right size, thickness and material.
My wine bottle wick was the right material but it was made of very fine filaments which were hard to keep in place.
As you suggested, I wet the wick before installing it and it does help keep the loose ends in place during re-assembly.

pennsydave,

I did find that blowing into the stack right after adding fluid breaks the 'bubble' that forms at the brass stack opening. The bubble is gone if I do a refill and leave it overnight - as George suggested earlier.

I've been putting the engine through it's paces and it's been smoking away after hours of operation (and many re-fills).


Thanks again to all for your posts,

Tom

This message has been edited. Last edited by: TomK,