I’ve got a new to me d21a-5 that I’ve been slowly going through now that the grounds frozen. I did the clutches and since I had the tank drained already cleaned out the banjo bolt screen and put a new fuel filter on. In the manual it says to just unscrew the manual plunger and pump it up and down to prime/bleed the fuel system and I can’t for the life of me get the plunger to move more than about 1/16” and it feels like free play not like I’m moving a plunger. I can twist it all day long in both directions. If I push really hard and turn clockwise I can get a couple turns on it and I lose the little free play I had, then counter clockwise and the same thing. I put my vac bottle on the bleed screw and pulled a vac till I got fuel and put the plug back in so hopefully once I finish changing fluids it will start, but does anyone have any ideas on what could be wrong, what else to try with the manual primer, or any tricks of bleeding air out of the fuel system another way?
Try to pull up or push down on the plunger a little while turning, If the plunger pops up then you can pump and lock it back down the same way you unlocked it. Hope this is helpful or some one who is very familiar with this particular machine will chime in and give better info. ALWAYS provide machine serial number with any questions and if the problem started immediately or slowly over time AND has any work been done recently to the machine and include any codes you may have.