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Having trouble with carb adjustments

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ChrisQ

New member
so I have a 91 Johnson 120 v4 (J120tlei) compression test checked out but she smokes terribly and dosnt seem to idle well at all. carbs look to have been rebuilt more recently and I cant find specific adjustments on the web. any help what so ever is appreciated.
Thanks guys
 
Diagram does not show mixture adjustments on that motor.-----------Have you done any other trouble shooting ?---------------Did this problem show up suddenly ?----Ignition output tested?--------------Looked into issues with crankcase compression?---------------Flywheel key ?
 
There are no carb adjustments. You have fixed idle air bleed jets, as well as fixed intermediate air bleed jets.
Any "playing around" with mixture is done by changing jets.
You do not want to get into that yet. Probably not needed.

Go to shop2.evinrude.com drill to your motor, and look at carb pages. You will see that the stbd side carbs have a different idle air bleed jet than the port side.

This would be the CARBS THAT FEED THE STBD SIDE CYLINDERS. This intake manifold system crosses over, in that the carbs that are physically on the port side of the motor feed the stbd cylinders. Same for the port cylinders.
A real good way to remember this is that the highest carb on the front of the motor feeds the highest cylinder on the block. (#1).

So, ensure that if someone has done the carbs, that the idle bleeds are in the right carbs, and that they are the right size (number).

Second, make sure the throttle bodies are clean.
 
If uncertain when the carbs were rebuilt last it wouldnt hurt to just put in new kits. That way you can check it is jetted properly and all the jets are clean. If you have any doubts just get new jets and install them with the kits. Call seaway marine with the model number they have the best books. Altitude has alot to do with jet size also make sure they are correct for where you will be running the motor.
http://www.seawaymarine.com/
 
I'm just getting my feet wet with outboard motors and have done some research. I went straight to the compression test to be sure it wasn't a scorched piston. I am un sure how to test the ignition output or the fly wheel although I would definitely like to do so now. about the fixed idle air bleeds. they are all very similar in size so how could I tell if they are mis placed? also do I need them snug or quarter turn open...? I got the boat last year and it seems rough at idle and every so often when I have the throttle set it feels like it would kick in and accelerate to where it should be and the rest of the time its running poorly. without touching the controls. . I think that would be the best way to describe it. also there would be times it could take 20 min to a half hour to fire it back up once I was ready to relocate to a better fishing spot. other times first crank. does this sound more like carbs or power pack?
 
The jets should be real tight. You may need to grind a wider screwdriver down to fit just inside the threads. There should be a number on the jets just take a soft copper wire to clean them out. A gas welding tip cleaner will work just be careful not to bore them out any larger. You can make a spark gap tester or buy one at your local auto parts store. It must jump a open air gap of at least 7/16 inch with a crisp blue snap on all plug wires. If you havent pull all the wire connectors and clean with electrical cleaner then put back together with dielectric grease. Clean all the lug connectors with a small wire brush including grounds. If a component use the mount for a ground take it apart and clean it also ae power pack and coils.
 
where can I find the proper diagram showing which carburetor pairs with the numbers that are on the idle screws? the parts diagram only shows a single carb not all 4.
 
Thanks. I ordered a starboard idle Inlet screw because I broke it when thinking it was an idle adjustment before I joined this thread. Only to find out in fact it's supposed to be a port side screw that's on the starboard side of the motor. �� Is there anyway to post videos on this thread so some one can hear the motor run and put me in the right direction? Something is slightly off and I've been told to go different ways by the few opinions I've gotten. It's a strong motor but it needs proper adjustments I believe.
 
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