The first thing I did when I bought my 2001 LS650 was to add an electronic tach. I found my RPM at 60 MPH to be right at 4000. I also found with a completely stock engine and exhaust system the bike would rev up to 6500 but realistically anything after 5500 and the engine stopped pulling hard. Like some of the others I found my top end was faster by about 5 mph in third gear than in 5th topped out at 72 mph and 3rd at 77-78 mph.
Then I junked that heavy sorry stock muffler in favor of an aftermarket Dunstal muffler. After drilling out the pilot jet plug and making some adjustments she would top out in 5th gear at about 80 mph on a long flat stretch (at least a half a mile). In my opinion still to slow to get to the top speed.
I am a prick when it comes to machinery not working the way I think it should so in December of 2012 I pulled the engine out of the frame and tore the top end off.
HORRORS
.....A flat top piston???(A dismal 8.5 to 1 compression)...In this day and age? And a disgrace for an exhaust port.
The engine is now back in the frame with a 97mm Big Bore kit with a Wiseco 10.5 to 1 forged piston, ported cylinder head and a Web Cams Stage III camshaft.
I hope that will fix most of the engine's shortcomings.