Topic: Best RPM operating range for a 77cb750k....?

[RjBu]

My bike has been acting strange, the acceleration from first is loafy and puttery till 3k and then it surges..? I replaced the plugs and that seems to have made it worse. No it will shut off randomly on me now and the crappy acceleration is the same. So i took the tank off and "looked" at the ignition system. I went through and cleaned the connections and when i got to the negative terminal of one one coils i noticed that it wasn't seated in the double female style plug receptor. Upon closer look i realized that the female plug had broken on one side so i jimmied it to hold it again but the problem remains. I was reading today that the bike should be operated at above 3k rpm. I definitely haven't been doing that with the crazy downtown city driving.. But icing on the cake, tonight.. i hit the starter and the headlights dim... nothing... so i gave her a solid kick and she ran kinda.... lost.... so idea about the bike... or advice on an optimal RPM range for normal driving would be greatly appreciated.

[TwoTired]

Check the battery

[RjBu]

Any thoughts on an optimal operation rpm range>? 

[Gordon]

Any thoughts on an optimal operation rpm range>? 

Between 3K and Redline.  Other than that it's a matter of personal preference, but your bike will perform better in the higher range.

Do what TT said.  The symptoms you describe point toward a near-dead battery.   

[asianq]

If battery is holding charge after you set it on a charger I would then look at your charging system.. ie stator, rectifier, regulator. Get a multimeter and connect to your battery. If you give it throttle at about 3000 rpm and your readings go around 13-14 you are good on your charging system. Also, have you done any mods on the bike or is it stock? This could affect how much juice is being used from battery, but if charging system is good then you shouldn't have any issues.

Ignition coils could also be getting bad as well, but usually you will notice your machine running much rougher since you would most likely be only working on a 2 stroke instead of 4.

Lastly, if all else fails make sure you also have a full tank of gas. I have had the imfamous surge when gas sloshes around in tank when fuel is low until it makes its way to the petcock. 

Good luck with tracking down issue.