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2stroke Johnson 4 hp tuning

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off_road

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"I have a 2 stroke '00 Joh

"I have a 2 stroke '00 Johnson 4hp outboard for my sailboat which doesn't run well.

I can get the engine to idle but when I try to rev it up, the engine boggs out and dies. Is there any good information on how to tune the 'air-screw' on the carburetor and also the ignition system?

I also think my timing is off when I throttle-up and that may be part of my problem. Anyone know about the timing and if I should check the points in the ignition system?"
 
"It has a CD ignition system s

"It has a CD ignition system so no points to worry about.

make sure you have a good spark at each plug and be certain that you have good plugs and correct type, QL86C ot QL77JC4, gapped at 0.030"

You will find instructions for setting the carb HERE but it it only has a slowspeed adjustment.

Maybe the carb requires cleaning."
 
Your carb only has low speed a

Your carb only has low speed adjustment which is fuel not air...handy to know when you want to richen or lean out the mixture.

It sounds like Vic said carby has a blockage in the mid or high speed stage... rip it off and give it a clean out with a carby kit
 
"Will do. What do you guys kno

"Will do. What do you guys know about the magneto (or, ignition module) and specifically the 2 pieces of metal that jut out which run close to the flywheel? Mine has moved since i've been working on it - is there any proper setting?

Good stuff, thanks."
 
"Pull apart the carb and rebui

"Pull apart the carb and rebuild /clean it. Most likely the shut-off valve and delivery system is partly blocked. Get the rebuild kit before You start, part no 0439070. Be careful with all small plastic bits and pieces, they break easily!
Use carb cleaner spray in the metal body, but keep away from the plastic parts.
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"
 
vics said:
"It has a CD ignition system s

"It has a CD ignition system so no points to worry about.

make sure you have a good spark at each plug and be certain that you have good plugs and correct type, QL86C ot QL77JC4, gapped at 0.030"

You will find instructions for setting the carb HERE but it it only has a slowspeed adjustment.

Maybe the carb requires cleaning."
Click to expand...
 
off_road said:
"I have a 2 stroke '00 Joh

"I have a 2 stroke '00 Johnson 4hp outboard for my sailboat which doesn't run well.

I can get the engine to idle but when I try to rev it up, the engine boggs out and dies. Is there any good information on how to tune the 'air-screw' on the carburetor and also the ignition system?

I also think my timing is off when I throttle-up and that may be part of my problem. Anyone know about the timing and if I should check the points in the ignition system?"
Click to expand...
off_road said:
"I have a 2 stroke '00 Joh

"I have a 2 stroke '00 Johnson 4hp outboard for my sailboat which doesn't run well.

I can get the engine to idle but when I try to rev it up, the engine boggs out and dies. Is there any good information on how to tune the 'air-screw' on the carburetor and also the ignition system?

I also think my timing is off when I throttle-up and that may be part of my problem. Anyone know about the timing and if I should check the points in the ignition system?"
Click to expand...
When it dies pull your spark plugs-will tell you a lot. If wet and "black looking"then too rich- CARB,. Light brown and dry-no/not enough fuel CARB. Make sure RIGHT PLUGS and check gap-should be .040. For your carb turn adjustment screw in SOFTLY until stops and OPEN back out 1/2 turn.If won't start and run open carb jet more but only a little each time.Is your fuel mixture 50:1 and DO NOT USE GAS WITH ethanol. Boat mechanics laugh at that up north as one of the worst things for small engines for starting/running problems, worse if sitting between fishing trips.
 
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