Logo
FULL SITE MENU

I have 2 3hp johnson outboards one is a jh19a other is jw19m they will only run with choke on.

R

redryder

New member
I have rebuilt the carbs but it seems like the are sucking air. I run it in a barrel without the air intake off the carb will that make a differance? Got new packing on the low speed adjustment.
 
They've been taken out,cleaned blew out with air hose.Can't see anything in the jets. It seems strange I have the same problem with both motors.Do these motors have crank seals. Looked up on the parts list and didn't see any!
 
The other limit to fuel is the float height. Unless something's been accidentally bent, it is unlikely to be incorrect, though.
 
The upper crank has a oil slinger but dont see anything for the bottom crank. They are both 1964 motors. Have you done a cylinder drop test? While running pull a plug wire and quickly put it back on. It should run on either cylinder
 
There are two marks on the bottom edge of the flywheel one for each set of points. On the points plate is a set of two marks. Use a timing light with a separate car battery and shine the light at the points plate marks while running you want the single mark on the flywheel to be inbetween the two marks on either plug wire. You dont need to pull the flywheel to adjust point gap to set the ignition timing. These little motors are real sensitive with ignition timing especially at slow speeds. Have you set engine sync?
 
Does the motor run better with the choke partially on??? More information is needed as to the actual symptoms.
 
There is a ceramic fuel filter inside the fuel tank. It often becomes clogged, especially if old gas is left in for any period of time. It is removed by removing the fuel line and unscrewing it from the bottom. You can clean it by back flushing it with carburetor cleaner.
 
Ive checked the float height and set it so it so it lets more fuel in,but then fuel will run out the carb so set it back where it was.
 
They will run on either cylinder,I've unplug one wire at a time and started them.I have choke it to start it all the time even after it is warmed up.In order to keep it running I have to push the choke part way in.If I push it all the way in it will rev up for a little while then quit.I really appreciate all the feed back,thanks!
 
Only running with the choke on smacks of dirty or wrong high speed jets. Are you sure they are clean and correct? They must be absolutely clean. Tank filter is a common problem, but generally will run for a short while before it starts conking out for lack of fuel.
 
Not meaning to insult you, but do you know what we mean by high speed jet? We are speaking of the "orifice plug" deep in the hole behind the hex drain plug. Don't be offended, but lots of people take those things apart two or three times before they even realize it is in there. You are supposed to use a special screwdriver to take it out.
 
Back
Top