Ruggerini Engine upgrade.

[Michael Gilbert]

Hi All, I am the proud owner of a Yanmar clone Enfield which I enjoy enormously. I have been considering an engine upgrade and after much deliberation I've decided that a suitable contender would be a Ruggerini MD151. Before I seriously start hunting for an engine there is a problem that I'm having trouble getting my head around, that's how to fit the engine sprocket.
The Yanmar (Winsun) has a 1" parallel output shaft and the sprocket slides on with a conical arrangement and locks in place on the keyway with grub screws. All the MD151's that I've seen pictures of have short tapered shafts, and I cannot visualise how to fit the drive sprocket.
If anyone has overcome this problem and would be willing to share said knowledge I would very much appreciate it. Michael.

[Michael Gilbert]

I am now in a position to answer my own question.
The Ruggerini MD151 has a long enough crankshaft to be able to turn it down to 1" for 3" and mill a 1/4" keyway in it. I will then be able to use the taperlock sprocket provided by Priceparts for my Winsun conversion. An added bonus is that the crankshaft hole in the Enfield Taurus primary chaincase is exactly the right size to fit the crankcase plate on the Ruggerini engine. The holes don't line up, but you can't have everything.

[Jeronimo]

There's another way you can accomplish this; I did it to mount a torque-converter on a Hatz 1B30 built as a static-speed genset engine, which had a short, 1" shaft that terminated in a taper and had no keyway. You can make, or have made, a split-sleeve (think of a wood router's collet) with a corresponding internal taper, and an integral, strong outer flange; then this part can be forced down into the sprocket hub by a bolt and thick washer in the threaded center-bore in the crankshaft. To remove, you can tap two or three holes in the flange for drive-bolts to retract the tapered sleeve from the hub. Worked well.