Mercury 200 22 HP 1960

When I first received this project I thought it was a total basket case ! Ugly unknown stuff with a seized piston and who knows what else would be all worn out.

When I decided to tear the machine apart for the parts and the learning experience of how it was put together the more I learned just how advanced Mercury Marine truly was in 1960. This was truly a great little engine.

Condition of receivership

This unit came to be with a seized piston, much dirt and a lot of Grime. It required a carefree attitude to get the piston out of it's bore.. (that seized in) Hammer was the tool of choice..

Now all apart and laying on the work bench, I pondered to review a 1984 20 hp model I had laying about it was total right off and I had just taken pictures of the useable parts to sell on ebay motors. Halted

Something sparked and made me wonder if the remaining piston of the ' 84 model would at all fit the 1960 model.    Other than a larger piston pin the pistons where the same. (24 years same wow)
The bore and stroke and the 84 model once fitted in had very reasonable ring air gap. .004 inches per inch of bore rule of thumb.

I borrowed a honing screw form a neighbour and cleaned up the rust from the block bore. I soon discovered both blocks where both called "hurricane", it impressed me ! Mercury for years had been truly improving their original designs.      Other than the improvement of CD ignition a smaller carb on the newer unit, a change of location of the Recoil and a switch in the lower unit design to manual shifting with the water pump below the waterline these engines where pretty much the base foundry same. But this Marc 200 recalls as 22 HP. I could literly view the many changes numberous people had put on this product.

I was dying to find out what a 1960 automatic boat transmission was all about? ...

Things I learned

The engines upper and lower bearings are the same bearings used on snowmobile back idler wheels, They cost $6.00 Cdn each. Just pop out the oil seals

• The prop turns backwards for forward thrust, the pitch is
   physically reversed on the prop.

• The points need to be set at 20 thousands

• The needle and seat in the carb may be repaired
   using four and six inline carb kits.

• There is only one gasket you need the one the motor
sits on and you can mostly make one

• Mercury beefed up the size of the motor bolts over the
years.

• They beefed up the connecting rods from 1960 to
1984.

When changing pistons use the existing newer connecting rod to mate with the crankshaft. Pistons should be reasonable to aquire as there are plenty of 20 hp units about.

The lower bearing should be firmly affixed to the crank shaft with the appropriate lock tite.

The 2 seals on the crank are still available

The water pump impeller is still available

When dismantling the water pump, use a metal bar that fits into the slotted holding nut and most importantly turn it counter clockwise to remove the water pump locking nut.

When taking the oil inspection plate off remember there are (2) two springs inside don't loose "one" I did. Well both are very light springs they make the transmission select their operations there is no shifting without these two small tossing springs they must be reinstalled properly. Take pictures

Recoil problems?
Need not be, they beefed up the recoil spinner and guess what? ! The 1984 recoil unit fits right inside the hood with all the "new" improvements intact, larger posts wider throw and better engagement locking.

Transmission, I took it apart for cleaning and only have a vague idea how it truly works, it is a matter of cleaver simplicity in one clean micro package F, N, R on one spring gear set, the lower unit holds nothing but a right angle gear set. The automatic transmission is mid mounted.

I was told to use racing gear oil in the entire housing (green) that is what I use.

A local marine dealer Rennies Marine a man with gleam in his eye and thousands of hours of Marine repair experience helped me through the learning curve of this dated machine. Rennie informed me the only items that took this motor down was the operators themselves, shifting gears from Forward to Reverse without waiting for the boat to stop "jam the gears" tended to break the spring .. Luckily I have a spare spring and gear set, noted to cost $500.00 on the free trade market of old is new again lists.. (see I told no one thanks)

Rennie of Rennie Marine also informed me that I was going to like this project as in the end once primed with fuel and set up right this engine started on one pull or you did something wrong. It did just that!

The other operators faulting(s) was no water from worn out water pumps and poor gas selections both
causing the engine to heat and seize
Run high octane fuel add octane boaster never use old gas. Setting the timing back a tad, will help. These where high compression outboards like all of Mercury Tower Of Power lines. For the water problem If it don't pee don't drive it.

Drivers Report
I ran out of time, winter set in and our lake froze over, all I got in was one test run. She clocked in at 29 mph on a small
aluminum boat, as the motor is a 20" shaft, the boat being a short shaft 15 inch unit, the motor dragged water, I am sure It will move out in the mid 30's if raised. However, the effect of spraying waters
kept the boat very firm on the water.

The engine ran very quite and was very responsive to throttle changes with a steady pull. We put it away for the season as the carb needle seat locked up. That is when I discovered the trick that the parts from other Tilston Carb's on 4 and 6 inline can be used.

Can hardly weight to make her fly next season. It's a keeper.

The Automatic Transmission
The transmission is a an interesting operating experience. Twist the tiller arm one way for forward the other way for reverse. 1960 Idea wow

Moreover, once placed in gear the motor speeds up in Reverse the back of the boat rises. It takes some getting use to. Note: as the tiller is used for all F N R + speed there is a throttle bar on the motor this allows you to set the actual idle resting speed. There is no clunk feeling when going from N into R or N to forward - Spring transmission takes up all direct clucking sensations. You Just GO

Starting this motor is much easier to start than our 1984 9.9 HP Mercury. Much less pulling, the size of the recoil is matched nicely to the compression.