Hi, my new to me bike was missing the oil pump, but has the drive gear still installed in the side cover.I purchased one online, used and the listing said It seems very clean but the small line that goes to the cylinder has a fixed brass ninety degree fitting instead of the banjo  What bikes have the brass fitting?Thanks,Thanks!

Looking at my parts books , the pressed in fittings arrived with the 74 DT 250 A .
Of more concern is the fact that the wormshaft protruding from your case ,
was different for DT 250 A, B , & C , and different yet again for the D & E .
This shaft matches with a drive gear in the pump , so it's very likely your pump
won't engage properly .
I don't know how your pump was described , but you really need a DT2 /3 pump ,
though a DT1 pump would work too .

Yes, absolutely, the pumps all look pretty much the same from the outside from the very first in 1964 to the 1990's at least.  

But they are different inside and the internal gear must be the correct ratio for the worm gear on the shaft.  There were a bunch of different pump gear ratios.

Thanks for the replies. the add read " Genuine 1971 Yamaha DT1 250 Oil Pump Assembly 214-13101-04 RT3 DT3 DT2 1968-1973" and was purchased on ebay. I have reached out to the seller for a refund. I appreciate the help!!

It could have been a NOS replacement part made a few years later.  Did it come in a box and/or does it have any numbers on the pulley?  Paint dot color?

Hi Mark,
the pulley has number 364 and 2 symbols, close together, a dome and a square pyramid, hope this means it's ok!

I've been able to determine the pitch of the gear inside the pump by pressing a strip of paper against the teeth and matching it to the drive worm gear.
I have a NOS oil pump in the box. Part # 214-13101-03. With the dome and pyramid on the pulley. It has the brass fittings in the pump body for both input and output lines.
According to bulletin # 394 in the tech library it is for the '73 DT3, which is the same motor as the '72 DT2.

Any paint dot?  When new they had a dot of colored paint on the pump body as part of the identification.
 

DEET is the expert but from what I've seen, the 364 pulley was used on several models and may have a different internal gear ratio.  

From what I see, the DT1 had a 55/1 gear ratio.  If you remove the clutch cover to get to the shaft, you should be able to "feel" if the worm gear engages correctly and you could even check to make sure 55 rotations of the shaft = 1 rotation of the pump

I'll check for a paint dot. Where is it usually located? Thanks.