High Flow Oil Pump to std. what's the difference

[surveywaters]

I have 2 oil pumps in hand my hands, how can I tell which is high flow?

Also, anyone have a tip for removing the oil pump drive sprocket? Threads are tight.

xr70

Edited December 14, 2011 by surveywaters
clarification

[surveywaters]

Okay, I got the drive sprocket off. I put some liquid wrench on the threads, lightly tapped it a few times with a hammer and brass punch, and let it soak while I made a tool out of an old screwdriver that resembles a tire valve tool. I had to use a piece of plastic between the drive gear and case to jam the gear and prevent it from turning.

The other tool in the image is a clutch nut removal tool made from an old socket.

Edited December 13, 2011 by surveywaters
additional info

[doopsx3]

xr50 is a standard pump...xr70 is the same as the hi volume aftermarket pumps

[surveywaters]

That's good to know. Now, the instructions for a high flow oil pump say to enlarge the orifice with a 2mm drill bit. Does this apply even if using the xr70 pump?

I have 2 pumps, both from 70's; one is chinese, one is honda. The Honda pump is thinner and has more lobes that are smaller. The chinese pump seems to move substantially more oil when operated by hand. This is what my question was really reffering to, I apologize for not being more clear. So what I am looking for is the design difference between an OEM 70 pump and an after market high flow.

[doopsx3]

if you are using astock xr/crf50 cases you will need to enlarge the orfice.....I like the Honda pump but the China pump will be fine