Re: Tillotson AJ29A x Home › Forum › Ask A Member › Tillotson AJ29A x › Re: Tillotson AJ29A x MumblesReplies: 5764Topics: 298 November 5, 2017 at 11:43 pm #67065 I don’t have a clue what the X stands for but you are correct in thinking the carb is from a ’49 – ’50 Merc 10 horse KF7. http://www.discount-marine-parts.com/tillotson_aj.html