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Discussion Starter · #1 ·
Ok, I am sure the answer is right in front of me but I am not seeing it. I am working on the rear set of cylinders/valve gear on a Regner TSSD 0-4-4-0 Mallet. She has full walschearts with lap/lead. I can get the forward direction set dead on with equil travel of each slide valve in relation to the ports. But shift the valve gear to reverse and it all goes to ****. Instead of being also dead on, it will pull the slide to far one way and barely uncover the other port at all. If I reset the motion to reverse being spot on, it throws off forward. What am I missing?
 

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Double check the eccentric crank (some say return crank) is set in the exact proper location. The crank is very sensitive and only needs to be off by a few degrees to cause timing issues. They are also very easy to get bumped and put the timing off.
 

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Discussion Starter · #3 ·
I have checked and rechecked them and have them set to assembly book. I have it much closer. The valve spindles have 2 adjustment points, the point where the slide valve is inside the valve block, and where the combination lever/eccentric rod attach outside the chamber. I have it set close enough that the rear chassis will run in both directions now. I am in the process of hooking everything back up to see if she will run on steam. Here is a pic of the rear engines valve motion work.
 

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Without seeing the valve myself, It seems like the combo lever is not designed properly. they are usually at about a 10:1 ratio and yours looks to be about 4:1. That could be causing your problem. Check that the valve is just opening at TDC in both directions
 
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