Johnson

Johnson, Evinrude, OMC, outboard motor, outboard motor repair, 9.9, 15 hp, date/year of manufacture, water pump, carburetor, long shaft, 15 hp conversion, sailmaster

Maintaining Johnson 8hp outboards

1986 - 1997, (Information & Observations)

Since I am more familiar with the 9.9/15hp motors, I will try to identify the differences between this 8hp motor & the 9.9s. I have had the use of this 1992 motor to use & examine it, so the following are my observations. It trolled all day long (7 hours) at a faster salmon trolling speed on 3 gallons of fuel. This motor would be a good choice for a lake trolling motor, but for even a 16' boat trolling for a bay type fishery where the current & or wind is prevalent, it just does not have the thrust to contend with the wind unless you speed it up considerably to counteract & keep it on course.

From what I can gather the 8 hp was basically an improved 7.5 hp & I suspect the lower unit is the same as used on even the smaller motors. These 8 hp shown here appear to have been made from 1986 to 1997. In the upper banner the picture on the left is for the 1986 version with the right photo of the 1992 to 1997. The motor I will be describing was made in 1992. It appears that the 86 to possibly 91 used the same earlier design as the 9.9. This one has on the nameplate made in Belgium, & another motor I observed did also, however they both were sold in the US. The connection to Belgium is not known, unless this was the first of the new design & was made there before the US could gear up for it on that model.

This 92 motor uses the newer type front mounted shifting lever & most other associated parts as the 93 & later 9.9 motors. The lifting / carrying lever is similar to the 94 9.9s. The tilting lock lever rotates instead of pivoting forward.

Front view	Rear view

The twist grip throttle & kill button are very similar to the 9.9 with the exception that the kill button is mounted in the handle about mid section & does not angle like the 9.9s, but is set at 90 degrees to the handle. It also has a friction lock similar to the Sail-Master 9.9s. The choke lever is in the same basic location, but is shaped different.

Left side	Right side

You will notice the newer type manual starter & flywheel similar to the 94 9.9 motors. The throttle linkage again is very similar also.

One thing was experienced is that the shifting lever HAS to be in neutral, otherwise if the starter rope is pulled, it may stick in the pulled position. It usually can be convinced to retract by moving the shifting lever to neutral, or into reverse & then back to neutral again.

The water pump pee hole tube comes off the left side's upper water jacket as compared to the later 94 9.9s.

There is no external power pack, so I can assume it is an Under The Flywheel type.

It uses the older small fuel pump. The thermostat is on top of the head like the 86 & later 9.9s.

The lower cowlings are made of plastic & similar to the 93 & newer motors, & uses the same basic upper cowling rear latch as the 93 9.9. There are no side cowling bumpers to protect the motor, but has rubber leveling pads on the rear of the lower cowling for support if the motor is laid on it's rear.

The lower unit is a unitized design smaller than the 9.9 & does not use the thru the hub exhaust. The water intake is in the exhaust tube right behind the prop as used in the older smaller OMC engines as seen by the screen hanging down in the photo below. The prop has a shear pin & the plastic bullet nose is just a retainer that is held in place by the cotter-pin.

This lower unit comes apart similar to the 9.9 for water pump repairs, except there is no shifting rod link coupler & screw. This motor does not use a vertical movement shifting rod, but a rotating one. The shifting rod comes off when you take off the lower unit. It has a flat on the upper end that engages into a slot in the pivoting shifting linkage inside the housing.

Lower unit & prop	Nameplate

As for repairs, it seems to be a very simple proven design that by my limited exposure to it the only thing I see a detriment is that you need a special flush unit as the regular muffs will not function.

Originally stated 09-16-2007, Last Updated 09-16-2007
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