| Also known as | E3907 |
| Diagram | Fig. 1 — CRANKSHAFT AND CONNECTING RODS · ref 6 |
| Subsystem | engine bottom |
| Listed in parts books | 1960–1962, 1964 |
Flywheel bolt
Flywheel bolt that secures the flywheel to the crankshaft assembly on the bottom end, PN 70-3907 (also E3907).
The 70-3907 is a flywheel bolt out of the crankshaft and connecting rods section, and it's a small part with a real job to do. It secures the flywheel to the crankshaft assembly, and the catalog record ties its position to the sludge trap arrangement inside the flywheel as well. Our catalog appearances for this one run 1960 through 1964, and it also shows up under the older E3907 designation, so if your parts book still uses that number, you're looking at the same bolt.
Read more
This is a bottom-end fastener, not something you want to guess on. Flywheel bolts on these engines are torqued and located precisely because they're holding a rotating mass together at speed, so fitment and correct hardware matter more than they might on a bolt somewhere else on the bike. Given the narrow year window we have on record for this part, check what's actually in your engine before ordering.
We stock it under 70-3907. If you're pulling the bottom end apart for a rebuild, it's worth replacing rather than reusing if there's any doubt about its condition, since it's not an easy thing to get back to once the engine's buttoned up.
Sorry if we got something wrong here. If you think this information isn't correct, .