Thursday, October 26, 2006

Cam Lobe marks


We have had communication about cam lobe marking seen on some bikes ranging from MY2000 F4 750 to MY2006 Brutale 910R. So far in every owner-group communicated case, the issue has been a visual one rather than something that degrades over time.

We have documentation of this condition over 33000mi/53000km with no degradation over time.

Via MV Yahoogroups and special thanks to AG, GB and PS:

If during service You find little "scratches" on top of cam lobe, don't worry. It is not a nice sight, but it won't give trouble. We have been monitoring this kind of problem for a long time and on many engines, and this is the conclusion we reached. The problem is due to a not perfect cleaning of camshaft before final treatment of nitrogen coating; some small patches of thin nitrogen coated layer detach from lobe, creating a kind of raw surface. This kind of wear is easily recognizable because it does not affect max lift ofvalve. If it happens to find this kind of problem on a customer bike that we service in R&D we don't change parts.

See photos: in this case it is quite small, but it can be bigger. The only true and dangerous problem is if the cam lobe is deeply worn, meaning it looses its shape and becomes flattened, loosing valve lift. In this case generally we change camshaft and buckets under warranty. This kind of problem is mainly due to a defective bucket. Hope it helps.

-courtesy AG


For reference here is a cam lobe mark at 34,000km/23,000mi:


Here is that same lobe at 33,000mi/53000km:



At 2:09 PM , Blogger shabir said...

is this covered under waranty ?


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