120 Johnson outboard

Checking a high/rough idle.
Engine running rough

[@tonygzz1000]

THANKS JOE FOR FIXING THE BOAT THE BOAT IS LIKE BRAND NEW NOW LETS GO FISHING 🎣

[@JoesBusBarn]

Hey there Jesus. Glad you like how boat turned out. Fishing we shall do my friend. SPI.

[@redragn72]

You still running her? It is so hard to find folks with this motor.

[@JoesBusBarn]

You were right. She was running lean. Supply pump was going out on her. Pump quit as we were in the lake trying to find the problem. Haven’t put boat in the water since. Waiting on pump kit. But yes. She will run again.

[@redragn72]

@@JoesBusBarn Good deal. This is what I bought as the boat came with a single pump on it and the "loppers" need dual pumps. The previous owner turned the red primer switch up that was feeding fuel right into the intake to mask the pump and loose bolt issues. www.ebay.com/itm/401369107682 I would still check the butterfly nuts and bolts just to be safe as they come loose often and even 10 inch-pounds can allow extra air leaning out the oil to much. Here is what mine was doing kzbin.info/www/bejne/mWaonKxopLl5aqM fun stuff. And in case you want some nostalgic factory how to. kzbin.info/www/bejne/mpbYp4GoodybgLM

[@JoesBusBarn]

Appreciate the info brother. Thank you. I am going to be working on it this coming weekend. Thank you

[@juangomez8186]

Is awesome the you can fix everything I been learning a lot watching your videos keep doing this my friend God bless you

[@richardluce775]

You’ll have a very tough time getting any big bore omc looper to idle properly on a flushette. He is correct all adjustments should be done “on the water” they rely on back pressure for proper operation.

[@redragn72]

she's coughing which means she is running lean. I would check the two bolts and two nuts for each carb butterfly bank. I had the same issue and until I started checking the torque for every bolt and nut it did this. So frustrating and if that cough continues you can hurt the cylinder walls in short order. High idle is due to it needing back pressure on the lower exhaust unit forcing the exhaust through the smaller outlet just under the cowl.

[@ct1762]

yep. it looked like the starboard side set was open a hair. definitely a mild lean sneeze. cam roller is probably holding them open. simply unscrew the set screw and the sneeze should go away. of course he now needs to remove throttle cable and do a full link n synch on the water. cheers.

[@ct1762]

looked like the starboard set of throttle plates were open a hair... all it takes. simply unscrew the cam roller set screw and see if it smooths out. its definitely got a mild lean sneeze. very mild, but the cam roller could be holding the throttle plates open. make sure its got its clear outer sleeve as well.

[@rudyflores9395]

awesome sir many talents

[@sergeylisovskiy-em3cr]

Hello. please help me. I bought a Johnson 120 and they gave me a lot of air jets for the carburetors. what is the sequence of their installation? according to the manufacturer's recommendations. I will be very grateful for the instructions. I am a fisherman and this is what I earn.

[@thomasarambasich7672]

I didn’t see any hose clamps go back on one of the carbs

[@jimmysteptoe4621]

Very good saying what he was doing with carbs. Great job. Jan.28 2024

[@greenbeist157]

That motor needs a link and sync I order to run right. Preform a link and sinc and you are done.

[@harveynewman4333]

anytime you clean, omc, plastic carbs, on the looped charged engines, you need to pull those tubes from the upper carb body.the ends of the tubes are size to calibrate fuel to blend with the air comming through the 2 jets in front of the carb opening. use a torch tip cleaner to make sure there clean. alot of times, soaking and blowing them out,does not clean them correctly.make sure to reinstall them back in the same holes. if not cleaned,you will get a sneezing idle,sounding like a missfire.

[@ct1762]

in 20 years, i have never seen anyone take them out. they are press-fit at the factory, and will not go in with a proper seal as its plastic. once you take em out it wont seal. also, nowhere in the factory manual does it say to take those out. ive never had an issue using a syringe and alcohol to clean these plastic carbs.

[@harveynewman4333]

@@ct1762 they do re-seal when you put them back. the only thing you have to watch is that you do not put them in to deep. you will block the openings of the orifice. i have had some carbs that were so bad that the only way to clean them was to pull them out. i have been cleaning them like that since the plastic carb loopers came out in 1985. never had any issues with any of them that i did.

[@harveynewman4333]

i forgot to mention that i also repair outboards for a living. i am, HJOUTBOARDS , here in highlands county,fla.

[@ct1762]

interesting. Ive never seen the need to do that, but not saying its incorrect just never saw it mentioned anywhere! I run an OMC rebuild shop her in RI as well. I will admit out of about 50 V4 looper rebuilds, i have had to replace about 3 carbs for whatever reason. probably the issue you mention, but I have so many spare parts i just swap em' out ya know?

[@harveynewman4333]

@@ct1762 i know what you mean. the worst carbs are the 60 degree,loopers with the bowls leaking and cracking. dont use the aftermarket bowls. had to many that i had to tap threads in to install the high speed jets. they were not threaded at all.

[@johnmullins1034]

Good information thanks got one doing same thing thanks

[@micahosornio8480]

I have the same motor mine has no spark any idea?

[@bago4205]

I'm having the same problem. Did you find the problem 😢

[@ole_mcd_farmn3357]

First 👍