Elektron Musical Instruments

Hi all. I have this little problem: whenever I use my machindrum as 
master clock of other sequencers and synths, it usually sends midi 
notes on the first channel of the selected machindrum channels (1-4, 
2-5, etc...). I usually end up selecting the 13-16 option and mute 
those tracks from my slave sequencer (yamaha rm1x). 

How can I prevent this? I'd like my machinedrum to send midi clock, 
but it also sends these notes (the same as hits are playing in MD 
sequencer). I think I've tried all options, but it still sends those 
notes. Anyone with the same problem?

If you have any ideas, please share. 

Thanks for your time.