Hi folks
Still looking for some one who can help me with  my yost action. I tried once before but the right person did not see my plea.
Thanks for looking.
Muskin

The main spring  broke. I made anew one, I mean  I made  many. Working the leaver it won't cock. Not sure if the sear is engaging the FP. I can't see much inside to tell what is happening. If I use a screw driver to push the FP to the rear it seems to engage the trigger and I must pull the the trigger to move the FP forward. With a main spring in it won't engage.

Thanks for your attempt to help me. I have all the prints I need. What I really need is to talk to some one who has worked on one of these actions. I had hoped I could find some one on ASSRA forms. Still searching.

Resolving the problem would likely be done rapidly hands on and there are those who could do it. Hazarding a guess is not comfortable gunsmithing!

There is no coil spring,  The action is cocked by the leaver pushing on the main spring which fits into a slot in the FP. When the FP is pushed back it rides over the sear. This is what I can not get it to do. Thanks for your advice though. Do you know anyone who can do this simple matter.

If anyone is interested check out JLouis suggestion to see the Yost action prints. You can see how it works. Thanks

Well folks I sent the Yost action off to Lee Shaver. Will let you know how that works out. Thanks everyone for your suggestions.

Yost Assembly Instructions:

1. Install trigger (8) from bottom of breech block (2) and insert 1/8" dia. pin (16). 
a. Install two trigger springs (13). Fasten with 8-32 x 1/8" modified screw (28).
b. Install sear engagement adjustment screw (25).
2. Lubricate top surface of firing pin (9). With breech block upside down, drop firing pin in and position to the rear of breech block.
3. Slide sear (6) in from rear into groove in firing pin and push sear pin (19) in. (May use slave pin or drill shank to help in assembly.)
4. Slip intermediate lever (5) with delrin bushing (23) on each side in from rear. Install intermediate lever pin (17) through intermediate lever (5).
5. Slip delrin intermediate lever stop bushing (24) in from rear and install (lever stop) pin (20).
6. Install intermediate lever torsion spring (12). Be sure that spring engages the upper notch in the intermediate lever and rests behind trigger spring screw (28). (May use slave pin to help center spring.)
7. Insert safety (10) to engage center (pivot) of torsion spring (12).
8. Insert screw driver blade into slot in forward end of firing pin. Depress trigger and slide firing pin forward.
9. Install breech block actuating pin (18).
10. Place tip of main spring (4) into slot in forward end of the firing pin. Position screw hole in bent end of main spring central to tapped hole and install 8-32 button head screw (27) using 3/32" allen wrench (33) provided. Do not tighten at this time. (By not tightening, the firing pin should be recessed into the breech far enough to allow installation of breech into frame without the barrel damaging the firing pin.)
11. Prior to installing the breech block, grease the breech block channel (mortise) in the frame with extreme pressure (EP) grease. Also, apply the same grease to front detent surface of the main spring and to the working surface of the lever (3).
a. Slide breech block into receiver (1) from the bottom along with extractor (11) and lever (3). Insert lever pivot pin (21).
12. Tighten main spring screw (27) firm enough to remove pretension on spring. Do not over tighten! Be sure hex key is new and sharp cornered and held firmly into socket.  I replaced my 8-32 button screw with a cap screw.
13. Install forearm extension (15) using flat head screw (29).