Tuning is coming along pretty well on my newly running 20B.  I have run into a bit of a snag.  Until last week I was running only on battery power, then I brought my alternator on line.  When the alternator is turned on, the engine starts to stumble and run rough.  As soon as the alternator is turned off it starts to run smoothly again.  Any suggestions for alternator filtering?

 

Thanks,

Joe

 

Joe;

 

You can try 100 mf capacitor between the alternator output and ground. 

Do you notice any other parameters changing besides the voltage? And how much does the voltage change.

 

I have not found it necessary to filter the alternator output.  If anything, my engine runs smoother with alternator on.  My conclusion is that I do my tuning with it on; voltage about 14.5v. Running with it off and maybe just under 12v changes the tuning a bit.

 

Al