Mark 30

[Matthew Pieklik]

Hi all, I am in the process of bringing back to life a Mark 30 That I picked up many years ago. Guess what, no plate with the serial number. How ever, I am fortunate enough to have the parts break down book that an old mechanic gave me. They list MK30 MK3E, MK30-1 MK30E-1, MK30-2 MK30E-2…….And so on. I believe I have a plain Mark 30 based on the Magneto. I have a Fairbanks Morse X4B70F with a serial number of 3966907. It looks like that Mag was installed on the early Mark 30 Can some on confirm that with me?Also, does Mercury put the serial number anywhere else on the outboard?
Seals–Have they been superseded 26-25837 26-25840 26-25431 26-20236 and 26-20070 Thanks , Matt

[dave-bernard]

pull the top cowl off on the flat in the top of the block by the exhaust and rear water jacket it will be stamped there. post it and I will give you the year. a pic might help also front face plate and side of top cowl. may help IF they were not changed.

[76-j]

Seals can be purchased from ANY reputable bearing supplier, generally a phone call away , if you supply them the Inside and outside diameter andthickness dimensions. Fairbanks magneto(s) were installed on Early Mk30, Kiekhaefer mags were installed on the last varieties,

[mercuryspecialist]

Happy New Year Matt and All,
Matt, Dave’s advice for locating the cylinder block stamped serial number is well taken. As you comment, the Fairbanks-Morse XV4B70F is indeed the original magneto, then you likely do have a Mark 30 or Mark 30E, or first serial grouping produced as a 1956 model. The “E” denotes an Electric model with electric starting and battery charging system. As to the oil seal part numbers, the 26-25837 and 26-25840 have indeed been superseded, but we strongly prefer the use of Viton lipped seals which we offer (@ 7.39 each) for use with ethanol gasoline. The remaining three part numbers have not superseded, but two are very long ago discontinued. As advised, with legwork substitutes may can be located at a bearing supplier. We do try to stock all of them, however, but I would check the outside diameter of the shift shaft bushing oil seal before ordering a replacement because the bushings were produced using either of two possible outside diameter and depth seals, and the parts manual may advise incorrectly when choosing.

Regards,
Joe
(770) 597-5992

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