seating fuel pump check ball's

Hello, Usually I search the archives and I can count on an answer, but, not this time! So hopefully someone can help me out. I have a novo 4 hp and it is slowly coming togather, I found in the archives to use mop cord and soap on the pump piston and it draws and holds suction , so I think it will work fine, However the check balls look o.k. , but the seats are a little crusty, is there a tool for re grinding/cutting or polishing the seats......?? Thanks Eric M.

I made a lapping tool from a pc of copper tubing with a brass ball soldered to 1 end.I bent the other end to a 90 for a handle.A little lapping compound and some elbow grease .The ball will only go acouple of pumps before it has a groove in it and needs to be changed or turned over.Rob

If you have access to a lathe make two laps, one with a 30 degree taper and one with a 60 degree taper. Use lapping compound to form a seat with a "point" in the middle. Make a ball lap like Rob uses and just touch it to bring the seat in.

Just put a drill bit of the right size and appropriate tip in a drill press. Take the fuel pump by hand and polish the seat by putting the drill bit against the seat. Clamping the pump down may cause the seat to be polished off center

epoxy a steel ball of equal diameter to a piece of copper - it won't wear out for a while. Andrew

I've had good luck in brass pump bodies by cleaning all the crud off the seat then putting a new steel ball of the correct size in the seat and giving it a tap or two with a hammer and brass drift.

I've also used this for making my own check valves. Drill the body then tap the ball into the vee left by the drill bit. With a magnifying glass you can see if the seat is good or needs another tap or two.

The brass housing is soft enough to take an impression of the new ball. It's always worked for me.

BTW, This message is coming to you courtesy of my 1948 Onan 5CW genset. Thunderstorms knocked out power last night and we're liable to be out for a day or two. That old sucker has really come in handy over the last 30 years!

Take care - Elden




Elden's Junky Web Page

Be careful using a drill bit in brass/bronze pumps.The material is very grabby with standard grind drill bits.it is real easy to ruin the seat if it sucks in.You can avoid this by flattening off the front of the cutting edge in the flute to parallel to a negative angle.Depending on the pump,when it was machined there will be a way to hold it in a mill vise that the seat will be square to the spindle for remachining.Rob

Thanks for the info guy's.......The pump is cast iron....I used a drill press and just held the pump against it enough to clean things up. I tested it and it is better already, once lapped in , using a ball soldered to a brass or copper tube I am sure it will be fine THANKS for all the idea's Eric M.

Run your drill backwards so it wont grab and will kinda polish. Nelson Yoder