1988 johnson 48 hp spl idling/running issues

bitpoop

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Joined
Aug 15, 2012
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3
compression was 150x2 after 8 hours on the lake 105x2.
last time i took it out it ran all day just fine then it only ran on one cylinder.
i putted across the lake on 1 cylinder and went home 6 years ago.
I put new plugs in, 105x2 compression, disassembled the carbs and sprayed carb cleaner thru the jets.
new gas, it starts up runs for a few then dies at high idle 1.5to 2k rpm's.
when it was running i twisted the carb linkage and revved it up both cylinders were hitting and u could feel the torque.
then it bogged as i tried to rev it up some more and died, like it was out of gas.
so i took out both plugs to see if they were dry, nope both vary wet with gas.
starts right up, when u lower the lever for idle u can here it missing and it dies.
and help?
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 1988 johnson 48 hp spl idling/running issues

Couple of things, will it run long enough to pull one plug wire at a time and see if you are running on one cylinder?
Have you tried squirting gas into each carb to see if it will pick up and run properly for a second?
Have you actually checked the spark with an air gap tester, spark needs to jump a 7/16" air gap and be bright blue.
How is the link & synk, adjusted properly?
Sorry, more than a couple.:)
 

bitpoop

Recruit
Joined
Aug 15, 2012
Messages
3
Re: 1988 johnson 48 hp spl idling/running issues

Couple of things, will it run long enough to pull one plug wire at a time and see if you are running on one cylinder?
Have you tried squirting gas into each carb to see if it will pick up and run properly for a second?
Have you actually checked the spark with an air gap tester, spark needs to jump a 7/16" air gap and be bright blue.
How is the link & synk, adjusted properly?
Sorry, more than a couple.:)

I ran a spark tester from the plug to the boot on each cylinder and ran the engine,
it was firing on both cylinders, it will high idle 1500 rpms for about 3 min. and when u twist the throttle it revs perfect then dies. when the idle drops below say 1000 rpm's u can hear it miss. choke it and it revs back up./no choke it dies.
I can't find any vacuum leaks.
i was told it would not start if the power pack was bad?
maybe bad thermostat not warming up?
would a vacuum gauge tell me anything on a two stroke?
i am going to go thru the carbs again/last time they look like new.
what does a bad reed valve do?
 

bitpoop

Recruit
Joined
Aug 15, 2012
Messages
3
Re: 1988 johnson 48 hp spl idling/running issues

cleaned out carbs again and it runs almost perfect.
it idles but the lower carb is not perfect as it will die unless i put my hand over the carb.
so it was the carbs .
 
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