Good morning guys I’m having issues with the oil pump on my 1970 Yamaha AT1 125
I’ve done everything except the seal’s which are on their way. The white gear on the left will turn when I start the bike , I’m running pre mix right now , starts then stops intermittently. Will that stop once I get the pump resealed ? It’s bleeds fine and I’ve got no bubbles coming out. The oil just won’t come out of the pump at idle or full throttle .The top end was bad when I got the bike so I’ve boarded it and finally got the carb straightened out.  She now runs like a champ. She’s been completely refurbished and looks amazing. Just need the oil pump straightened out and she’ll be done. Thanks so much everyone and Merry Christmas to all.   Lew. 

Not that common to not have a pump fail like that.  

First thing to look for is make sure the pin sticking out near the pulley is still there.

Second thought is maybe it's your expectations?  How much oil are you expecting it to pump?  At idle, the pump puts out a drop every few seconds.  Even with pulley rotated to full throttle, it puts out only a few cc's every 200 pump strokes...  pump drips oil, doesn't "gush".

Internals on pumps are tricky, if yours is bad, I'd send it to DEET to troubleshooting/repair.

I’d be thrilled with just a drop but not even that. I’m also aware of the 10 cc at full throttle for 200 turns. Like I said I can bleed it but that’s as far as it goes. From what I can tell all the pins are there. The seals are original so we will see. Is Deets the one who will rebuild them for 350 bucks ? Seem expensive to me. Thanks so much for your comments.  Lew

I haven't heard DEET's pump rebuild price in a while but I doubt it's anywhere near $350 unless maybe the pump needed a ton of work.  Last price I remember wasn't much more than HVC Cycle charges for their rebuild kit.  Well worth having someone that knows what to look for do it, especially if you have no output.

The only pump I ever had that didn't work had been "rebuilt" by the previous owner.  There are some tiny little pins and springs that are easily lost and it is possible to assemble it incorrectly.

Another thing you could check is remove the outlet port banjo bolt and check the check ball and spring underneath it.  I have seen crud build up at the ball.