Johnson J6RCDE PRIMER

[Maureen47]

I’m trying to help a friend get this ‘ol thing running.
He does not have the operator’s manual nor have our attempts to find one online have been successful.
The decals beside the primer knob are worn away.
Does anybody know the proper operation of this thing? (A choke would have been so much simpler)

thanks in advance, Ed

 

[oldboat1]

Primers bypass carbs for starting -- hand pump/primer fills the carb bowls and push fuel past the carb to the cylinders if the primer is activated. After the motor starts, activating the primer pushes fuel past the carb as well (primer is not a pump). The red lever should be parallel with the primer body for running.

 

[racerone]

What-----There is no red lever on the primer of this 6 HP motor !!

 

[Maureen47]

What-----There is no red lever on the primer of this 6 HP motor !!

Me thinks oldboat1 has the larger engines in mind!
This little engine has a plunger type arrangement adjacent to the carb with a suction line from the float bowl and a discharge line to the carb body (in the throat area). There is a red ring on the plunger/knob about a third of the way out. The cowl mounted instruction decals are worn and un-readable. No operator’s manual available.
what I am asking for is instruction on how to operate this thing.
Thus far I believe I have been flooding this thing on initial starts; re-starts are no problem as this “enrichment thing” is not used once the engine warms.
Otherwise, I have this little thing running like a stripped monkey!

Thanks again of the help, Ed

 

[CatTwentyTwo]

LeeRoy's Ramblings is an excellent source of information for the older motors.

https://www.leeroysramblings.com/OMC 6-8hp.htm

Choke / Fuel Primer : These motors used 2 types of choking systems. The 1984 and 1985 used the conventional butterfly choke. 1986 thru 1989 used a combo choke/fuel primer system. They reverted back to the conventional choke system in 1990, WHY ? A guess is that when these primer chokes work, everything is fine, but as they age, weird things start happening and if there is any fuel contamination, this is a logical location for it to collect. Actually it was not a choke as we know it, but merely a system that injects a small amount of atomized fuel directly into the carburetor throat, or intake manifold (depending on the model).



This primer system used a knob similar to and in the same location as the butterfly choke knob but in use, this choke knob is actually a dual function choke and primer system. As you pull the knob all the way out it is injecting fuel into the intake (it's like a syringe and you can feel the tension as it's squirting the fuel into the carburetor) this is the primer function. When you release the knob it should go back a little over 1/2 of the way in by it's self with the red ring at the base of the shaft still being visible, this is the choke position. After the motor has warmed up a bit, you have to push the knob in all the way (it snaps in), which is the running position.

Fuel Primer unit exploded view diagram	Fuel Primer symbol decal on front of cowling

If your motor has this fuel primer system and you are having problems where it seems that your motor is starving for fuel, or runs better with the breather off, and you are beating your head against the wall trying to figure out what is wrong, look at this type a primer unit. There is a distinct possibility that if the internal O-Rings are worn AND/OR the plunger is not fully retracted, you may be getting a air leak into the fuel system. Or it may not be seating when pushed back in, thereby could be allowing extra fuel into the carburetor, flooding it out.

 

[Maureen47]

THANK YOU, THANK YOU, THANK YOU Cat Twenty Two!!!
Exactly what I was looking for.

Ed

 

[oldboat1]

Whups! sorry Ed!