New guy here looking for help with a Johnson 1993 120 Looper V4

[reddragon72]

Been reading and watching posts and decided that all that reading is leading me in circles.

I bought a 1993 Cajun 1850 with a Johnson 120 V4 Looper. J120TLATF
When I got it the boat was idling high in the water around 1200-1600 RPMs in gear. It would run all the way up to 4500 RPMs and start to plane and then start falling back to idle then go up to 3000 RPMs then fall to idle then run back up to 2000 RPMs then eventually just idle at WOT.

Wait about 45 seconds at idle then go WOT and the same thing happens. When I got it back to the ramp to load it the motor would not stay running at idle. Also when I bought it I found out later that the primer lever is supposed to be in the 6oc position but it was in the 12oc so I turned it down and things got worse and would not fire up and run unless in the 12oc. Now that the carbs are rebuilt the primer seems to do nothing at idle anymore like the engine is getting to much fuel or it is no longer needed except start up as the carbs are getting filled up now.

Here I am today.

https://www.youtube.com/watch?v=c5Eky2oTF4A

I have rebuilt the carbs, the floats were set so low that they barely moved in the bowl. so I adjusted them. The bottom right carb was dripping fuel when the bulb was squeezed when I go it and no that no longer happens. The VRO pump was removed and replaced with a single pump and I read that that it needed to be a synced two pump setup so I built one myself and it is working fine and pushing lots of fuel out.

As you can see in the video it starts right up every time and slowly dies. There is a lot of smoke when it "coughs" sometimes. I also noticed that the number one plug wire, when on the timing light, would not fire off each round but that could be due to the timing being off from the lean or rich mixture. Two recirculating valves are bad, both on the top. I read that you can order inline valves but I am not sure where to get those as the line is thick but man the hole in it is tiny!
I want the cough fixed before I go back out onto the water.

So before I blow this thing up screwing around with it I am looking for help.
Thanks

 

[healey8390]

If your ignition system is good you should get constant spark regardless of a rich or lean condition.

I’d do a spark test on all four cylinders. Spark should jump a gap of 7/16 of an inch.

Have you checked the throttle linkage? Does the trigger advance/move back, when you throttle up and down?

 

[racerone]

Report some facts.-----What are the cylinder compression numbers ?----Does spark jump a gap of 7/16" on all leads , yes or no ?----Have you checked the flywheel key ( timing ) ?----And no you can not find a sheared key with a timing light !----Looked into possible issues with crankcase compression ?

 

[reddragon72]

Let me do all of this. The guy I bought it from gave me a sheet from six months earlier from a marine shop in south Houston that showed 123+/-2 on all cylinders but I will order a compression tester and will check myself. I need to get something to test the spark that big. I do not have anything that can do that.

 

[tblshur]

local auto parts have adjustable gap spark tester also loan a tool compression gage hope this helps

 

[reddragon72]

local auto parts have adjustable gap spark tester also loan a tool compression gage hope this helps

I'll call in the am.

 

[reddragon72]

On these motors does the exhaust come out of the prop? If so my prop is shiny on the outside and fouled on the inside. I can wipe away the carbon. Also the plugs do not have a typical elbow sticking out just a point in the middle. I've seen these on racing engines but not everyday engines.

 

[racerone]

Exhaust comes out the prop at full throttle.----Is this your first outboard motor ??

 

[reddragon72]

Exhaust comes out the prop at full throttle.----Is this your first outboard motor ??

Yes. All others have been inboard. But still in the video you can see the exhaust coming out of the prop so it does come out there in idle. This is why I asked the question.

 

[racerone]

At idle in the water may be different.------But yes on a hose the smoke blows out the prop.

 

[reddragon72]

At idle in the water may be different.------But yes on a hose the smoke blows out the prop.

So it creates backpressure. Ok. Is that the what the small rectangular hole it for between the clamps on the back?

 

[reddragon72]

I came out this morning and noticed a puddle of black oil under the prop. It is coming from the front of the prop that meets the unit. Is this normal?

 

[reddragon72]

finally did a compression check. I am not sure if I did it right but here are the numbers.

1- 90
2- 95
3- 90
4- 100

It is a compression kit I ordered from Amazon and has a hose so I am not sure if that is affecting it as I heard that it might.

I looked for steps on how to and I read to pull all plugs and turn it over for 3-5 sec. Did I need to cut the fuel off as well?

Also spark was good and blue at night and constant on all packs. I also pulled the NGK surface plugs and put in the Champion regular plugs.

Thanks for any help