I just purchased a boat with a 1990 Johnson 60. The previous owner had some things mis-adjusted so I was rechecking and trying to correct them. The engine has the single mark throttle cam part # 431707. At 5000 RPM, the timing is correct at 18 degrees BTDC. At slow idle, it is about 8 degrees ATDC. The book says it should be about 2 degrees ATDC. The timing pointer is correctly dialed in and I am using a good tach and timing light. The engine seems to run pretty well as is but I think the idle should be better than it is and 8 ATDC seems strange to me. I am using the correct 1990 Johnson factory manual and the setting of the idle timing is not addressed for that throttle cam. Many thanks for any help.
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