Having problems adjusting the #6 plunger to maintain a consistent flow at low RPM's to high RPM's. Readings at zero throttle @ 400 rpm would only get 7 to 8 ml for #6 and the rest would be at 13-14ml. So I adjusted #6 a few times only to get it up to 8.5ml. Then at a flow test with max throttle @ 2000 rpm numbers 1 - 5 are between 43 - 44.5ml and # 6 is at 52ml. When I adjust # 6 back down for the 2000rpm test then at a zero throttle @ 400rpm its at 5ml and the rest are at 13-14ml.
Recheck the TDC plunger heights and all 6 are in between 0.5 & 0.6mm. So I remembered the problem with all the corrosion on the #5 & 6 plungers and cylinders. I had a difficult time cleaning #6 piston top area.
Wire brushed it to death but still would not slide into the cylinder good. Seemed to bind up halfway in. So I used some very fine grit, 2000 emery paper to clean it up. I spent about 30min cleaning, or should I say sanding that plunger before it would finally slid through free.
Well the problem is that I over did it. I most likely took off all the sharp edges at the top of the plunger and also increased the clearance between the plunger and cylinder. I also cleaned out the cylinder bore. What was I thinking?
Lesson learned. I have another pump that's missing front & side covers so I will dissemble it and get a plunger & cylinder out. I'll start testing again by tomorrow I hope.