johnson 4 hp deluxe ?

odds

Recruit
Joined
Jun 30, 2009
Messages
3
i have a johnson 4 hp deluxe on my sailboat model #j4rdhlesr, does anyone know the year of this motor? also, wondering what the twist knob next to the choke is and what the best setting is for it. motor runs good but seems to foul plugs. does anyone know if this motor has a way to set for shallow water? and where to buy a manual?
thinking about buying a 4 stroke 5 hp honda, any suggestions as to which motor would push a 21' sailboat better?
Thanks much
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: johnson 4 hp deluxe ?

1990 4hp Johnson. Twist knob is the slow speed setting as follows below. A manual can mosty likely be found on this site.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

Note 2: If the engine should be a three (3) cylinder engine with three (3) carburetors, start the adjustment sequence with the center carburetor.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 

odds

Recruit
Joined
Jun 30, 2009
Messages
3
Re: johnson 4 hp deluxe ?

thanks Admiral, adjusted that and she is idling better, lots o' smoke though gonna get some new plugs it has champion QL77JC4 in now , does that sound correct, anyone know the gap?
the person who owned it before me always started it with starter fluid, it starts now without but takes some work!
anyone know what to replace the brass pull cord grommet with, this one has been pulled so many times its worn out and wears out the pull cord, good thing i have a padlle.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: johnson 4 hp deluxe ?

Starting fluid is a no no as it has no lubricating qualities. If you're going to spray anything in that carb, use a spray bottle containing premix.

Set plugs to either .030 or .040, whichever works better for you.

Mixture is 50/1. One pint of 50/1 TCW-III oil to 6 gallons of gas. A octane rating of 87 will be fine.

If still hard starting (and you have good spark), the carburetor most likely could use a good cleaning.

That pull cord eyelet can be replaced...... part number 331977 .
 

odds

Recruit
Joined
Jun 30, 2009
Messages
3
Re: johnson 4 hp deluxe ?

Thanks again Joe,
i'll put in new plugs and give it a whirl, if that doesn't help then it's time for a rebuild on the carb.
gotta get her running good were havin' good wind the last few days!
 
Top