Very Ugly pictures of a Very Nice ATV engine gone boom.
This Guy Scooby runs a Bombardier DS650 ATV, "slightly warmed over" cough cough.
2001' EFI/Turbo Alky DS650, 90+ ft-lbs, 120+HP? Yup.
His story is:
It looks like the heavier intake valves floated at above 10,000RPM which caused all kinds of damage.
I was working on ignition timing and jetting to dial in upper RPMs when things went bad as motor reved more freely.
I had my rev limit set to 11,000RPM.
I had PAMI valve springs in which do not have enough seat pressure for high RPM.
Everyone should know what their maximum safe RPM is for the valve springs and cams they have installed.
Guess I need to talk to DSMIKE and find out what valve spring setup he uses that enables him to turn 13,500RPM with .450" cams.
http://community.webshots.com/album/147781566JRvSHh
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