broken valve spring
Turbo Mini Forums

pulled the head today to change the leaky bk450 for a cometic,

was just about to torque the head back down and noticed a broken spring on no1 exhaust,

any ideas what could have caused this? or is it just down to a duff spring.

also its not seen mega rpm, limit is set to 7k and itrs only seen that a few times.

sometimes just happens.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

You would need a really good look at the fracture face to see what caused it, ie, fatigue or more likely an inclusion in the wire it was made from.

Only the evidence will have probably been long lost by the two bits rubbing against each other....

Lucky you had double springs......

An inclusion in the wire the spring was made from is most likely IMHO.

Schrödinger's cat - so which one am I ???

cool cheers guys,

most likly is a dodgy spriong then, puts my mind at rest...

come to think of it i may have noticed a shuiny patch on that spring when i had the cover off last.

still looks like my misfire is gone (fingers crossed)