point set for johnson 1968 3HP

floyd36_

Cadet
Joined
Jun 20, 2004
Messages
28
Hi, can you tell me how much i have to set the point of this engine i think its .020 but not sure and for the low and hight speed adjust for the carb. its 1 1/2 turn to begin??

Thanks you!
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: point set for johnson 1968 3HP

Have the flywheel key aligned with the fiber rubbing portion of the points, then set the points whereas a .020 gauge will pass thru but a .022 will not.

(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 va /lve 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, wating 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.
 

floyd36_

Cadet
Joined
Jun 20, 2004
Messages
28
Re: point set for johnson 1968 3HP

Ok i set the brand new point at .020 i change coil, clean carb. and pump filter, now i have fire on plug and gaz on carb. but engine dont want to start... both cilynder have 70 psi compression, dont know what to look, someone can help me??????

Thanks you!
 

floyd36_

Cadet
Joined
Jun 20, 2004
Messages
28
probleme with johnson 1968 3HP

probleme with johnson 1968 3HP

Ok i set the brand new point at .020 i change coil, clean carb. and pump filter, now i have fire on plug and gaz on carb. but engine dont want to start... both cilynder have 70 psi compression, dont know what to look, someone can help me
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: probleme with johnson 1968 3HP

Re: probleme with johnson 1968 3HP

Try making up a spray bottle (like a windex bottle) of fuel/oil mix and spray a little down the carb's throat. If it fires on that then there must be a fuel delivery problem like a clogged carburetor.

70 psi should be fine to start with. Put the throttle about 1/2 to 3/4 to full to start.
 
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