Spring has, errr sprung...

Dukedesmo · 24-03-2024, 09:02 AM

Strange indeed, never seen such a failure before but the good news is that the seal looks fine and a new spring fitted though I doubt it would actually make much difference without a spring? other than maybe on the front cylinder exhaust where the oil pools around the valve.

The (complete) spring is a circle with OD of 12mm, ID 10mm, 1mm thick so call that 11mm overall length, in which case the circumference (C=2pi r) should be 34.56mm and I have 34mm so I'm saying it's all there or at least any remaining fragments are so small that they should get caught in the filter so I can't see it being a problem.

24-03-2024, 09:02 AM	#1
Dukedesmo Registered User Join Date: Sep 2010 Location: Leics Bike: M900 Posts: 2,844	Strange indeed, never seen such a failure before but the good news is that the seal looks fine and a new spring fitted though I doubt it would actually make much difference without a spring? other than maybe on the front cylinder exhaust where the oil pools around the valve. The (complete) spring is a circle with OD of 12mm, ID 10mm, 1mm thick so call that 11mm overall length, in which case the circumference (C=2pi r) should be 34.56mm and I have 34mm so I'm saying it's all there or at least any remaining fragments are so small that they should get caught in the filter so I can't see it being a problem. __________________ M900, 916, LeMans II. Last edited by Dukedesmo; 24-03-2024 at 02:36 PM..