MERCURY - What motor ?

B

black427

Recruit
Joined
Jun 11, 2004
Messages
1
I have a 1960's vintage MERCURY that I need to identify in order to get parts for it.<br /><br />On the front plate it's written on an oval plate Kiekhaefer Mercury and tree downward pointing arrow heads.<br /><br />The engine looks like a Mark 55 1956-1958 but the boat it came with is only rate to a max HP design of 40 HP. So it's only looking like the Mark 55.<br /><br />The serial number is 2347359, and it's written on the engine mount.<br /><br />The number written on the frost plug is 27935.<br /><br />The carbureter number is 20188.<br /><br />The magneto number is AJ51A.<br /><br />The starting is manual but there is a place to put an electric starter.<br /><br />Large chrome covers on the side of engine.<br /><br />Originally the engine foot is white with the top a light blue.<br /><br />The Mercury sign on the side of the engine is written in wavy script.<br /><br />Thank you for the info !<br /><br />Martin
 
Chinewalker

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: MERCURY - What motor ?

Hi Martin,<br /> Sounds like you've got a Mark 30. It's the only one that looks like a Mark 55 that used the Tillotson AJ51A carburetor (along with its racing sibling, the Mark 30H). The Mark 30 used a similar powerhead to the 40-cubic inch Mark 55 with smaller bores for 30-cubic inches. It also used a slightly beefed up Mark 25 (18hp) lower unit, and as such it is a bit on the delicate side with 30hp running through it. Keep the unit FULL of lube and free of water. Also, if it has a brass/bronze prop on it, save that for the mantle and get a good aluminum prop for it. The Aluminum prop is MUCH easier on the gears, particularly when shifting due to it's smaller mass.<br /> Your motor's serial number doesn't correspond to any Mark 30 serials, as they were generally in the low 1-million, high 900-thousand range.<br /> By the way, the Mark 55 was called the Mark 55 because it debuted in 1955. It's actually 40hp...<br />- Scott
 
You must log in or register to reply here.
Top