MTH PS2 Steam Engine Runs erratically

did you try a factory reset from conventional 1 W  n 5B in one second intervals, if the reset works you should hear 2 whistle toots to let you know the reset worked. if that does not correct the problem, maybe a tach reader problem or bad board , if you wanted to prove it just try another good board from another ps 2 engine and see if the same system occurs if they don't your board is bad!

Alan

is it a ps 2 5 volt board or a ps 2 3 volt board?

Check the flywheel tape and tach reader gap.  This sounds like a dirty flywheel tape or bad gap on tach reader.  At faster speeds it can loose tach of counts and speed up.  G

G,

I am really not that technical when it comes to trying to work on these engines. About the extent of my technical expertise is replacing a traction tire, battery or adding a BCR. I am not opposed to taking this apart but when I do, I'm still not sure what I am looking for when you refer to the "flywheel Tape and Tach Reader Gap".  Is this something that would be fairly obvious once I remove the shell? 

Try checking the connection between the engine and tender. If you have a wireless tether they do come loose on occasion. Frustrating, good luck.

G

I've removed the shell of the engine to take a look at the flywheel tape. The tape looks to be in pretty bad shape with what appears to be scratches all the way around it. I've tried to include a picture of it but I've never attached a photo to a post before so I hope it works. The photo isn't the greatest but maybe you can see from it just what condition the tape is in.  

You already know the answer., get a new timing tape.  In the mean time you may be able to temporarily fix it  with a black magic marker,      It seems something's been or is  rubbing on the center of the tape . good  luck.

I agree with the above comment. You need a replacement tach tape, and while it is apart, a new tach reader, the price is minimal, compared to taking the loco apart twice. I do this kind of work, but you are in New Jersey, which is a fair ride from where I am in PA. 

I would use a marker to replace those black stripes or you can get a tape.  The other issue is cleaning the tach reader with some alcohol.  It looks like the bracket may have been pushed down and rubbed on the flywheel, or the motor mount was loose.  Make sure all is tight and gap about thickness of a dime.  G

I'll give the marker a try and make sure all is tight for now. Would I be able to order the tach tape and reader from MTH? Would anyone know the part numbers I'm looking for. The parts diagram for my particular engine is not showing up under the support tab on the MTH web site.

Using a metric ruler measure the diameter of the flywheel.  Is it 27mm or 30mm.  Based on that I can mail you one.  E-mail in profile.  G

G,

I tried the marker and it actually went around the track half way and came to a screaching halt. It would go in reverse fine but still kind of acted the same way in reverse. I could not get it to go again in the forward motion. It would go for a short distance and then stop. My guess is that the flywheel tape is just in to bad of shape. I've sent you an email with the size of the flywheel.

Mailed the tape, but I think you have some sort of binding or other issue.  Does the motor turn by hand easily with no binding.  Is there excess lateral motor movement.  G

The motor does turn by hand with no binding or lateral movement that I can tell.  I'll try the tape and see if that resolves the issue. If not, we can discuss the possibility of sending the engine to you for further repairs.

Thanks, Dan 

G,

Finally got around to installing the flywheel tape. I'm still having a problem with what appears to be, as you said, a binding issue. The engine does run just fine in reverse but it will only go about 3 MPH in the forward motion before it starts to bind.  Is it possible for the engine to move in reverse but have still have a binding issue when running  in the forward motion?

Thanks, Dan.

You may have to pull the motor,( Hopefully just  a couple of screws)   and test the running gear for blinding.. you can use your hand or push it on  a couple of  pieces of track. Are all the 1/2 moons on the drives in the same position.  How about the screws holding the side rods on... is there a slight amount of slack or movement on the side rod  at each screw?   

Are you still getting   marks on the timing tape?  Maybe something 's still  going on there.

If you can  determine that the running gear is ok . put the motor back on a test again for binding .   good luck. 

Works in one direction, binds in the other is frequently the result of something loose or misaligned. Check the tightness of the motor mount and the motor, and also if anything is loose in the gearbox. 

Yes, Based on the tight clearance on the joints off the drive shaft I think you might have to slide the flywheel closer to the motor, or slightly bend the motor bracket to gain a gap.  Different directions create different thrust force and move the motor shaft back and forth.  In forward what ever direction the shaft is moving it may be binding.   G