Motorcycle Repair: 1977 CB550 high rpms, long stroke, redlines

Question
Bill, my 77' CB550 F seems to have very high rpm when I am on the highway. At 63mph the RPM is 5K, I am afraid the engine is running to hard. Is that too high rpm? Also, when the engine is hot, the idle rpm is about 2800 in neutral. Any advise.  Thanks Brooks

Answer
That sounds about right to me.  My 69 CL450 ran 6000 rpm at 60 mph in 4th and 5000 rpm in 5th.  You can go up a tooth on the front sprocket and it will slow it down sum but you'll notice a reduction in acceleration.  That engine redlines at 10,500 rpm if I recall correctly so 5000 rpm isn't too bad.  Those engines are designed to rev high.  Unlike a long stroke Harley.

The engine should not idle more than 1000 rpm.  If the carbs are synchronized correctly and the idle air adjustments are correct, I'm guessing the timing advance unit is warn out.  

Good Luck
Rich