We have produced a set of titanium valve retainers for RC390's, you may ask why we would do such a thing? We have found that with extended high RPM usage the stock valve retainers will fail. The angles between the collets and the retainers do not match well enough for them to hold they valve clearance for very long, typically resulting in zero clearance. This becomes an expensive issue to replace the finger followers and cams on a frequent basis. An additional benefit is increased valve control due to the slightly reduced retainer weight, we also increase the preload on the spring to bump the seat pressure. These retainers also use the much more commercially available 9.48mm valve shim which is much easier to find then the KTM 9.5.
KTM RC 390 Titanium Valve Spring Retainers
Pictures of the damage.
KTM RC 390 Titanium Valve Spring Retainers
Pictures of the damage.
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