adjust or pull carb now?

6228SH

Petty Officer 3rd Class
Joined
Jun 14, 2007
Messages
77
'62 28 horse johnson- I've rebuilt the carb,and adjusted low speed needle to Joe Reeves method in a tank,have high speed 1 1/2 out.I have been troubleshooting what seems pretty lame wide open preformance.today I had my Daughter squeeze the primer to see if perhaps the fuel pump wasent keeping up and the engine bogged way down and never recovered.getting dark, we limped back to the dock.I have had the carb apart a couple times and the float is sitting parellel to carb body. does this sound like a problem adjusting high speed needle could fix? if so,how can I do so under load? the boat ramp is usually busy ,so doing it on the trailer isnt an option and I dont have another driver to enable me to do so while going down the water. at this point it seems it's getting too much fuel but beyond trying small changes and then firing it up to see if it's better or worse I dont know what to do- any advice welcome! Steve
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: adjust or pull carb now?

If the engine bogged way down when the fuel primer bulb was pumped, either the float is off level, the float needle valve needs replacing, or the fuel pump diaphram is cracked/broken.

The high speed jet must be adjusted when the boat is under way unless one has a test propeller. You cannot adjust it otherwise. Find someone that can either operate the boat safely or one that can understand instructions in adjusting the high speed needle valve. 1-1/2 turns open is a starting setting. The engine will not run properly without adjusting it properly from that setting.

(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle valve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top 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. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, 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.

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store
 

6228SH

Petty Officer 3rd Class
Joined
Jun 14, 2007
Messages
77
Re: adjust or pull carb now?

interesting-I will replace the diaphram,and go from there,THANKS!
 
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