Hitchcocks Forum

How critcal is the weight and balance of the crankshaft on my 1951 350cc Bullet?
The reason I ask is I've just split my crankcase on my supposedly rebuilt engine to find that the
timing side flywheel looks like someone's taken a hammer and cold chisel to it. the drive side one isn't as bad
but still damaged.
I could file and grind them smoothe but would the affect the weight and balance to a serious degree?
Dave

Hi Dave - don't worry about it, these cranks are so heavy to begin with that a few ounces wouldn't really be noticed. I have swapped from alloy to forged steel conrods and swapped all sorts of pistons on these machines without rebalancing and with no ill effects. I restore the balance factor to the original setting after lightening flywheels, but this is after a few pounds in weight has been removed from them! Cheers, Paul.

Thanks Paul
Would you still recommend tidying it up, taking the rough bits off which may, possibly, come adrift
with the rotation and heat?
Dave

Hi Dave, yes, tidying it up a bit wouldn't hurt one bit. Cheers, Paul.