As I'm sure many of you are aware and most likely long ago complied with, Rotax issued a Service Bulletin (SB-912-043-R2 and (SB-914-029-RB) back in November 2006 which in part called for replacing the radiator cap part no. 822075 (0.9 bar) (13 psi) with a new radiator cap part no. 922070 (1.2 bar) (18 psi).

Perhaps you just wish to replace you cap because its been 10 years and it does have a rubber seal. You can buy one from CPS for $84 or Lockwood for $70. Or much better still for about 1/2 that cost you can buy the same cap online from a BMW motorcycle parts dealer. As you might have seen on the Matronics email list, The single cylinder 4-stroke BMW F-650 liquid cooled engine (1997-2000) was made by Rotax and uses the same 1.2 bar cap.

The BMW part number is 17112345074. I just bought one from Rick Johns of BMW Motorcycle of Escondido, in California.

For less than $40 it's an exact match for 922070 both in appearance and fit.

Blue skies and tailwinds,

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Good info.

Thanks Larry

If one uses Evans waterless coolant it would not be an issue, as the high boiling point does not produce much if any pressure on the system.



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