1986 Johnson 9.9 J10RCDB main jet

[landover50]

My grandpa passed away a couple years ago and while cleaning up some of his stuff last week I found an old Johnson 9.9 in a corner and my grandma told me to take it and get it running. After a little bit I got the darn thing started, couldn't believe it.

I'm getting into the carb, cleaning it up and going to do a rebuild. Is the main jet located under the compression plug with the red arrow? This is looking at the bottom of the carb, above bowl. If so, how is it removed? I removed the plug and it looks as if the jet inside can be removed with a screwdriver. I attempted, but it doesn't seem to want to come out. It will rotate but doesn't seem to go out or in. Hoping I haven't ruined something. Thanks for your help.

 

[kbait]

Main jet is on the side of that post.. just run a thin wire through it and blow it out.
Under that plug is a brass nozzle..not to be removed..
Good luck!

 

[landover50]

Main jet is on the side of that post.. just run a thin wire through it and blow it out.
Under that plug is a brass nozzle..not to be removed..
Good luck!

Thanks. I definitely twisted that brass nozzle. Will that cause issues?

 

[landover50]

Main jet is on the side of that post.. just run a thin wire through it and blow it out.
Under that plug is a brass nozzle..not to be removed..
Good luck!

Okay kbait, I ended up doing exactly what you told me not to do. I had turned it prior to my original post, so I proceeded to turn it to make sure it was seated correctly........ And I turned it all the way out. Rookie mistake, I know. I think the issue is it is threaded from the top so instead of tightening it I was threading it out the other way. Are there actually threads that hold it in? I was trying to re-seat the nozzle and it doesn't want to. Not sure if I have the correct idea of how to get it back. How do I re-seat that nozzle?

Also, there are small holes/ports in the nozzle. Are they supposed to line up front to back with the main carb body or side to side? Hoping I haven't done something irreparable. Thanks for your help.

 

[kbait]

Not sure on threads.. probably just bonded in somehow. Also not sure on those holes/orientation. Probably oriented to the side to help fuel atomization. You could try locktite.
You could also find a used 9.9 carb easily, as folks often switch to 15 carbs..which are hard to come by. I have a couple 9.9 carbs.. IM me if interested..

 

[landover50]

Not sure on threads.. probably just bonded in somehow. Also not sure on those holes/orientation. Probably oriented to the side to help fuel atomization. You could try locktite.
You could also find a used 9.9 carb easily, as folks often switch to 15 carbs..which are hard to come by. I have a couple 9.9 carbs.. IM me if interested..

I actually have an Evinrude 15hp, it's what I use now. It's kind of beat up so maybe I'll throw the 15hp carb onto the 9.9. I've seen/read quite a bit on the converting the 9.9 to 15. Is it as easy as swapping the carb?

 

[kbait]

If your 15 is ‘74-92, 15 carb should bolt up and give more hp.

 

[landover50]

If your 15 is ‘74-92, 15 carb should bolt up and give more hp.

quite positive it is. I'll have to dig into it and see if I can swap. And not take that nozzle out this time.......Doh.

 

[landover50]

If your 15 is ‘74-92, 15 carb should bolt up and give more hp

K bait, any idea how far the nozzle is supposed to extrude into the carb? You were right, it's not threaded. I've got to figure out how it's seated in there but need to know how far it needs to be pressed in. Thanks.

 

[kbait]

K bait, any idea how far the nozzle is supposed to extrude into the carb? You were right, it's not threaded. I've got to figure out how it's seated in there but need to know how far it needs to be pressed in. Thanks.

Top of nozzle looks to be exactly 1/2way though carb bore. I can see hole facing forward..pics

 

[racerone]

The opening of that nozzle is right in the center of the VENTURI.-----When air rushes through a venturi the pressure drops.-----Then atmospheric pressure acts on the fuel in the float chamber.-----The fuel is then metered into the airstream via a calibrated hole in the high speed jet.

 

[landover50]

Thanks for the information, appreciate it. But it appears that mine may be different. As you can see in the pics I have the nozzle about half way into the venturi but the small holes aren't exposed like the others above. With it inserted half way like pictured it is also very loose, like it's not where it's supposed to be. I also noticed the difference in color of the nozzle itself as you can see in the pic. Do you think the difference in color indicates where the nozzle was inserted to? I'm thinking the dark coloring should sit flush with the bottom of the venturi tube?

 

[racerone]

Replace the carburetor.-----Not hard to find.

 

[landover50]

Where's the best place to find them? I googled and didn't seem to be a lot of options.