awesome , that's a nice looking pumper, and also very impressive numbers for 4 strokes.. The only thing that dawned on me about the pump exertion is the preload on the check seal in the valve.. If there is a problem there, you are physically fighting that along with prior pump pressure in the valve.. Something worth looking into/.. thanks for posting
[img]https://lh3.googleusercontent.com/eOVhIy-FrrRNJrSxMd8sDs1k3DlgQtoCiVnGePSqGgIV97c1_19S4A1p5YkpnVv2oqTwgxWqNkjhw_A=w1199-h614-rw[/img]
Are my eyes deceiving me or is that the Daisy 880 rubber baby buggy bumper?
that's really odd. is it smooth but simply locks up at pump 5
I wonder if that rubber bumper is making too much friction /suction on the back stroke. Maybe Bill has some insight from the 880's
Quote from: Rob M on October 14, 2017, 09:56:29 PMthat's really odd. is it smooth but simply locks up at pump 5The hard part is the last bit to lock the pump arm, and almost as hard to release the pump arm to stroke again. It's not locking up, it just requires way more energy than I want to put in. 5 pumps is doable, I can go all 8, but it's unreasonably hard. I can cock all of my magnum springers offhand if need be no problem.
Quote from: Sky on October 14, 2017, 10:01:26 PMQuote from: Rob M on October 14, 2017, 09:56:29 PMthat's really odd. is it smooth but simply locks up at pump 5The hard part is the last bit to lock the pump arm, and almost as hard to release the pump arm to stroke again. It's not locking up, it just requires way more energy than I want to put in. 5 pumps is doable, I can go all 8, but it's unreasonably hard. I can cock all of my magnum springers offhand if need be no problem. for now , I'm still blaming the valve .. no , it wouldn't affect the backstroke , but certainly the closing force.
I figured it was a basic crosman esq valve layout.. but yes, try a lighter spring and see if it helps