Well, tried one of Duke’s 288 oil pumps…won’t fit
At first I thought the thin o-ring just needed to seat. Nope., pulled it and still not fitting. Then noticed the little 6mm o-ring was doubled, and, the pin was a good 2mm proud. Fixed that and tried again. It was better but still wouldn’t seat flush, even without the thin o-ring. something isn’t lining up.
Measured the diameter of the section that seats into the bearing seat. Within a couple thousandths of oe and well under the bearing seat diameter.
Stumped.
Through the old one in…fits as it should.
At least the oiler gear fits, very snug, but fits