How many turns out do you set the low idle jet from lightly seated

[909]

... on a 1993-2002 9.9hp Johnson Evinrude.

Had to set it around 3.5 turns to get it to idle in a bucket without sneezing or dying.

Seems high, the older generation was only 1.5 turns

 

[jimmbo]

I suspect the carb needs a thorough Cleaning

 

[909]

Did a thorough ultrasonic clean in the machine.
It's the plastic carb 255cc not the all metal 215cc

 

[jimmbo]

And you blew out all the passages with compressed air, and returned the carb to the Solvent for more soaking a few times?

 

[909]

I did 3 x 10 minute intervals with 16 to 1 rapid cleaner @ 30 degrees .

Blew out the passages

Used a thin wire.

 

[jimmbo]

Can you provide a Model #, so I can look up the correct carb?

 

[909]

J10RE0E

 

[jimmbo]

You are adjusting Screw# 15? Did you have/use Rebuild Kit? If no, what parts did you replace?

 

[Scott Danforth]

Did a thorough ultrasonic clean in the machine.
It's the plastic carb 255cc not the all metal 215cc

did you pass a fishing line thru all passages?

 

[909]

Yes screw #15 . I didn't use a kit .

I used a thin guage wire.

 

[909]

I've gone through 3 carbs and they all seem to need at least 3 turns.

Some need 4 turns

 

[flyingscott]

That may not be wrong. It seems like the plastic carbs do require more turns out to run.

 

[909]

Thanks. Between 3 to 3.5 to 4 turns seems to work.

 

[kbait]

Use a magnifying glass to look for a crack in the plastic carb top #10. That will cause a lean idle issue.

 

[909]

Luckily no cracks. I've also heard the top can warp.

Everything is working, as it should.

I suspect 3.5 turns is normal on plastic. 1.5 is normal on metal.

 

[racerone]

It would have to do with the pitch of the threads on the needle.----And the shape length of the needle and passage ways in the carburetor.----

 

[909]

After a bit of research, I found that Leroy's mentions :

The "Go To" thread back out to begin your idle setting will be about 4 1/2 threads out from bottomed out. I have found that on my motor about 4 5/8 turns out seems to be about right. The reason for this number of threads turned out instead of the 1 1/2 for the pre 93 motors is that these later plastic topped carburetors have a finer threaded idle needle. Like 0.45 MM per thread (or near 50 TPI) where the pre metal topped carburetors have 28 TPI.

This would mean I'm running lean @ 3.5 to 4 turns, or that their version of seating the screw is more agressive and requires more turns. My version of lightly seated is just that .... lightly seated.