First Yammy, need mo' powa!!

I like having the lower speedo... it makes it less likely that I'll do something really dumb on it. Hell, that's why I ride a 550 in the first place.

 

Believe me if you take the time and tune the bike you will be suprised at what it can do.

Thoroughly clean carbs, synch carbs, colortune and re synch carbs.

The difference between a fouled plug and a properly burning fuel mixture will be night and day on the bike.

This really isn't alot to do on a bike from the 80's.

Hit the throttle on an xj650 thats properly tuned and it will definitely throw you back and I'm no light weight.

 

I don't think anyone mentioned this, but a larger front and smaller rear sprocket will lower revs as well. Acceleration will suffer, but the same is true with using a larger rear wheel.

 

Full fluid and filter change, new plugs, valve clearances checked & shimmed and a proper carb balance would be where I would start. Know where you're too before you set off making too many changes. If your motor is down on stock power, trying to regain it by tuning is like ripping up $20 bills in the shower.
Stokie

P.S. Try rev'ing the nuts off of it right up through all the gears and only change up when you feel the 'pull' start to tail off - ignore the noise it makes. That may give you a better idea of it's top end.

 

XJ650's have no chain They are shaft drive.

 

Know the power of the dark side young Skywalker.

 

I commute on my 750 daily, 70 MPH is about 5500 RPM and it regularly sees 100+ MPH with no problem passing trucks. Something is wrong with your bike good luck they are great bikes.

 

Great bikes but something seems wrong on yours or ur just being too gentle with it.... get on her!!!