Merc 100 what to watch for what to offer

[hmai]

Guys i have always been a 1950’s OMC fan (rebuilt several), but looking at trying a Merc for my winter project. I have seen what I am assuming a late 60’s Merc 100 in the local craigslist. Shifter in front, but jet black. Good candidate for restore?

Anything i need to look for. Obviously besides compression, shifting? I do know some of the electrical can be a little pricy. Known problems with lower units etc.
For example on OMC’s u always have to watch for the bent shift craddle.

Also, whats the going rate for a complete non running Merc 100? Needs at least a cosmetic restore.

[dockbuster1]

The merc 100 was an automatic spring drive the lever in front is a throttle for neutral ,the motors were original white. When Mercury came out with the full gearshift it was called the 110 to differentiate it from the spring drive ,however the motor has a great deal more power but the water pump and spring drive can be difficult to deal with . Good luck

[jpatti75]

As Callie30R mentioned, the Merc 100 and 110 are very different motors. First, figure out if you are actually dealing with – a Merc 100 or a 110. If it has a shift lever and original black paint, it is a 110. If the shifting is accomplished on the tiller handle and the motor is white (assuming someone didn’t paint it black at a later time), then it is an automatic transmission Merc 100 from the early 60s. Both motors have their merits, but the automatic transmission is a much different drive system and a bit more complicated to service when it comes to the water pump. I personally like the automatic transmission motors, but they do require special tools and patience to work on. If you are looking for a Merc project motor, you just need to decide how much of a challenge you’re up for. The 110 will be easier to service and is a solid motor, and a bit easier to get parts for since it was made for so many years (granted there were changes over the years). The Merc 110s of the 70s moved to different ignition systems, and sometimes those can be pricey to replace when compared with the traditional magnetos offered throughout the 60s. There are still parts for the 100s, just don’t expect to change a water pump impeller in 20 minutes with a couple basic wrenches and sockets.

As for price, condition, location, and personal desire are all factors — there is no set answer. If the price seems worthwhile to you for the condition, go for it. Expect you’re going to have to put some work into it no matter what. The 110 was produced in abundance, so it shouldn’t be too difficult to find one without paying a ton.

Here is a YouTube video of a Merc 100: https://youtu.be/paro9ETeNzQ

Here is a 110: https://youtu.be/3Eu5zysLaJg
Hope that helps.
JP

[billw]

If you’re looking at a true Merc 100, it is an "automatic transmission" model. Non-believers in the Dark Side call it a spring drive. (Lol) While there is nothing automatic about them, they are odd, clever and complicated, compared to a clutch dog-type engine. They are my favorite type of old Mercury, mostly because, in classic Mercury fashion, there was a lot of outside-the-box thinking going on, when they designed it. The only thing about the 100 I don’t really care for is that it is the lowest power output version of three basic automatic transmission hp ranges, that ALL WEIGH PRETTY MUCH THE SAME! They are the smoothest of them all, though. I would prefer the extra power and speed of a Mark 28 or a 200 (or even a 250, if you stumble across one) but that’s just my opinion. The 110s have fewer cubic inches; so they have less real power; although they are a lot lighter and are also good runners. In my opinion, the 110s lack character; but to each his own.

Price depends entirely on physical condition. A cream puff that doesn’t run is worth FAR more than one that someone has spent a ton of money to get running but still looks like a wreck. Therefore I would give a huge range of $25 for a real ugly one to $400 for a near mint one.

Long live American manufacturing!

[jeff-register]

Bill,
I hear you…a 250 in good shape!

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