Making a flywheel puller for the MHR Mille - Anders Hortvedt, Norway - home

As you can see from the drawing, I am no mechanical engineer, so the drawing does not follow any known standard :-) But for such simple parts, I think it should be able to understand what I mean, even with this dubious drawing quality.

The extractor consists of 2 turned parts and 2 M8 screws. In addition, you will nedd a standard 3-legged puller. The turned parts are

The crancshaft endpiece, made to protect the crankshaft end and to have some steady rest for the 3-legged puller. The endpiece is made from a 8.8 steel M14 bolt. This is the lower part o the drawing.

The mushroom-shaped piece to be mounted outside the primary gear on the crankshaft. I made it from aluminum , as that was what I had at hand. The 20mm thickness of the mushroom head has the same reason, it was what I had. I'm sure 10mm would be sufficient. It has a 26mm hole in the middle to clear the 25mm crankshaft. It is mounted by removing 2 of the original 6 M8 allen head screws holding the flywheel to the primary gear, and mounting this piece outside the primary gear using two longer bolts. These bolts must NOT protrude any furter into the flywheel as the original ones do, or else you might destroy the starter sprag clutch. As you see, I have turned the piece to clear the heads of the 4 remaining screws.

When the mushroom is mounted, remount the crankshaft nut (I didn't, and the flywheel jumped 30 cm off the shaft and down on the floor), place the 3-legged puller over the edge of the mushroom, and place the crankshaft endpiece in the crankshaft end. Place the puller's spindle against the countersunk hole in the endpiece, and pull the complete setup off the taper. If no luck, use gentle heat and at last, a blow with a hammer and a soft drift directly on the flywheel.

Hope I have made myself understandable.

Anders Hortvedt