change of clocks

[Carter]

Hi, wondered if there are any electrical gurus who may be able to help me out . I'm looking to find out if the standard rev counter is  part of the engine management ? Just bought a 98 600 with an acewell digi speedo/rev counter. The bike was running rough so have stripped and cleaned the grubby carbs . I've read that there's a set up job with the TPS and the rev counter but have no rev counter so wondered if the throttle position and indicated revs work the advance and retard ?  If so, I'll pick up a cheap set of clocks and bung the rev counter under the seat but if there's a way to bypass or trick the system I'd rather do that.
I'm not even sure if there's a problem but it'd be another thing to look at if it's not a carb/inlet rubber or spark problem. Not had time to pop the carbs back on yet so just testing the water.
Thanks in advance for any help or advice .