120 Johnson Dies

[d18]

Last fall my 1988 120 Johnson was fouling plugs at lower speeds,
I changed all 4 needle valves and seats this spring, now it seems
to not foul plugs, but wants to die at mid speed, runs great at high speed,
and lower speeds, just not at mid range.

Any ideas what to look at?
I was thinking the mid speed jet, but it seems unlikely that all 4 could be plugged?

Thanks,

T

 

[kevinj]

You need to do a spark gap test to make sure you're getting strong fire to each cylinder.

 

[racerone]

Are thermostats installed on this motor ?

 

[d18]

When it dies, giving it choke picks it back up to get to higher speed.
I am not sure if the thermostat is in there, but I don't see why it wouldn't be

Thanks...

 

[Boobie]

If you have to choke it when it wants to die you may have a fuel pump problem.