Forum

[Isettaman]

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

[Bullet Whisperer]

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.

[Isettaman]

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

[Bullet Whisperer]

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