Topic: '72 CB750 top speed?

[Dunk]

What should the top speed on a '73 CB750 be? Topped mine out at about 90-95 today trying to keep up with my crazy buddy on his Shadow 1100. First time I really opened it up and I'm a little disappointed. I expected more with all the hype of 110 MPH cruising speeds and such. I'm perfectly contect with the 60-70 I usually do though. haha

But anyhow, I am not sure on the exact speed as my speedometer reads a little fast according to local radar displays, and my needle was just about to 100 so I suspect 90-95 is an accurate range. Not sure at what RPM though as my tach cable is sticky and sometimes works others not. Felt like it was breaking up at that speed though, almost like points bounce in a car. My points are only a couple hundred miles old though. I don't know, maybe it's something else entirely.

Well I'd aprpeciate wahtever input you guys can give. My engine does not pull hard above 6500 RPM or so as I'd expect it to. Is it a bad thing if my car's engine pulls hard to a higher RPM than my bike's engine? 

[KB02]

Two questions:
1.) What is your gearing?
2.) When was the last tune-up?

[BobbyR]

Your motor should pull very well at 6500 and above, you should check out your tuning as suggested.

[Dunk]

Not sure on gearing, I'll count sprockets and let you know. What is the stock size sprockets?

Last tune-up was about a month ago (maybe 400-500 miles).

My timing is unstable. It will vary about 2*. This is due to the advance mechanism sitting in the crank (I think) hole loose. The hole is oblonged. I a considering using the drillable/tappable JB weld stick stuff to fill the hole and make it fit the advancer more tightly. I also need to get my timing equal between cylinders. Two cylinders are 2* retarded from the other two since there is not enough adjustment in the points plate to take up the slack from the oblonged hole. I think when I fix that it'll help.

Also I have 4 into 2 turnout mufflers on the bike and a nifty higher flowing air filter. Jetting in the carbs is stock. Thoughts?

[mlinder]

Your timing is off (randomly) and you are likely running lean.
That would explain a lot of your problems.

[BobbyR]

One half of the motor is fighting the other. You can make the holes in the points plate longer, or you can change the point gap until both are equal. With these crappy pods a lot of people report sidewinds and other vortices causing running problems. With the pods and open exhaust you are lean. With the timing all over the place it is amazing she runs as well as you report.