2004 Johnson 115 V4 low speed needle valve adjustment

Hello all,

I have a 2004 115 Johnson that has idled like crap since I bought the boat last year so this year I decided to rebuild the carbs and make sure everything was in good shape. Now that I've got everything back together, I find that it still runs like crap so I checked the idle timing with a light, 4 deg ATDC just like it should be. I have the factory manual and it suggests to fine-tune idle with the low speed needle valves. When I rebuilt the carbs, I counted how many turns off the seat each one was...8-9 turns depending on the carb...and made sure I put them back in the same number of turns of the seat when I reassembled. So today, I tried changing the needle valves to see if I could get it to run any better...I did, but found I needed to turn the screws in ~5 turns more (3-4 turns off seat).

Long story short, does anyone know how many turns off seat the factory recommends to set the needle valves at to start fine-tuning?

I just want to make sure I'm not way off base with the setting I have now (since it is so different than the way the motor came to me) and that it's not something else I should be looking at.

Thanks in advance!
-Ryan

Re: 2004 Johnson 115 V4 low speed needle valve adjustment

Mod number of engine??

Re: 2004 Johnson 115 V4 low speed needle valve adjustment

Engine model# J115PLSRC

Re: 2004 Johnson 115 V4 low speed needle valve adjustment

Hi ryan, i looked at the parts break down for you johnson 115 and it looks like the same carbs that are on my 98 115 evenrude, my evenrude shop manuel says to start them at 5 and three quarters out then fine tune them , you have to do this in the water at the lake at neutral trim , i tried to do it in a water trough ,i ended up with a smooth idle but when i took it out to the lake it wouldnt idle i fine tuned them by doing it one at a time at the lake than going out and give it a try , they say to have someone drive the boat in gear at idle speed and you turn in mixture screw till engine SPITS BACK OR COUGHS THAN BACK THE SCREW OUT A LITTLE I DID NOT HAVE ANY BODY AROUND AT THE TIME SO I WENT BACK AND FORTH FROM THE LAUNCH TO MAKE ADJUSTMENTS AND THAN BACK OUT TO THE LAKE , MY 98115 EVENRUDE ENDE UP AT BETWEEN 6 AND 6 AND HALF TURNS OUT ON ALL FOUR CARBS THAT IS WHERE IT WAS FROM THE FACTORY.

ALLEY MECHANIC

Re: 2004 Johnson 115 V4 low speed needle valve adjustment

Thanks Alley...that's about where I'm at to get it to run as good as I can so at least I know I'm in the right ballpark...

Re: 2004 Johnson 115 V4 low speed needle valve adjustment

When 'finished' adjusting, pull the plugs and check that they are even in color and 'dry'.

Re: 2004 Johnson 115 V4 low speed needle valve adjustment

You'll never get dry plugs when idleing. The only way to check them is to take the mtr out and run the heck out of it and immediatly shut it off. Then check them. Plugs will always look different at idle speeds.

Re: 2004 Johnson 115 V4 low speed needle valve adjustment

boobie said:

You'll never get dry plugs when idleing. The only way to check them is to take the mtr out and run the heck out of it and immediatly shut it off. Then check them. Plugs will always look different at idle speeds.

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Do not quite agree when it comes to these engines(60 loopers) and the 'Y' plugs.
If adjusted correctly, temp is where it should be, they might be slightly moist, but not wet or black.
Runing on muffs a different story, but run at sea under real conditions, yes.
Decarb the engine, run it hard for a couple of minutes, change plugs to new and adjust.
When finished adjusting, give it a burst, let it idle for about 5 minutes and check the plugs.
If plugs are not 'in good condition' and equal in color and dry/moist, start all over again. (providing compression is good on all cylinders).