Mills Bonus Horsehead Slot - Problem with BONUS unit synch

[sbmania]

I'm working on a Mills Bonus Horsehead slot with the cheater mech that only allows B-O-N-U-S letters to be achieved every other play. It works correctly and I have no problem synching up the letter mechanism so that the B comes up when the first reel says B etc. However, periodically, the unit goes out of sync and the O for instance might award an N instead of the O. When I follow the procedure to get it back in sync, it will play correctly for a while and then go back out of sync.

I'm assuming the letter wheel with the notch in it is slipping somehow and causing award of the incorrect letters. Not sure how that wheel is supposed to stay in place and not slip. Anybody smarter than me who can give me some tips on what to look for? Thanks!!

[capt7310]

Hello, Go to You tube and look up Mills Horse Head Bonus by Coin OP and Dave Burriti shows you how to re-set the mechanism. Good luck

[sbmania]

Thanks! I'm able to set it correctly but after a few dozen plays it doesn't stay set. The letters go off sequence again. But it will play correctly and award the correct BONUS letters for a while after I set it up. It just won't stay set.

[radiorich123]

Check for worn parts in the bonus meck. Could be a lose cam or shaft.

Rich

[sbmania]

One of the on-line videos shows a set screw down near the star wheel and says not to touch it. Anybody know what it does? I kinda want to touch it! Maybe its loose and allowing the star wheel to slip?