1994 Johnson 120 V4 will not stay running. Please help Frustrated!

[jstatham]

Hello everyone. I just got the boat and motor last week and both have been sitting for a couple of years. Here is what I have done so far.
Johnson J120 TLER

1. Compression 120 all cylinders
2, Rebuilt all 4 carbs
3. Replaced Fuel Lines/Filter
4. New Plugs
5, New waterpump impeller and housing
6. Removed VRO fuel pump and replaced with new non vro pump.
7. New Thermostats
8. Rebuilt Fuel Primer solenoid

Ok now here is the problem it will not stay running. The top right plug seems dry and when it is running I am seeing a snake like spit coming out of the Air Bleed Orifice on the front of the carb with the dry plug. I have pulled carb off several times and check the float and checked for debris or blockage and everything is fine. At this point I am scratching my head and not sure what to try next. All the carbs air/fuel mixtures are set to 2 ½ turns out. The butterfly’s are all shut. Do I have a stuck reed valve? Or bad stator or ??? I have posted a video of the engine running and pictures of the plugs I am not sure what to do or try next. The fuel bulb is tight and I get the same results if I keep pumping it while running. I don’t believe it’s a fuel issues at this point. I am planning on cranking it tonight to see if I can see any spark coming from under the flywheel but the stator and powerpack look new. Any help will be greatly appreciated.

Here is a link to the motor Running. I had to split into 2 movies so there may be a little overlap


http://home.comcast.net/~jkstatham/movie1.mov

http://home.comcast.net/~jkstatham/movie2.mov

 

[jstatham]

I also forgot to mention that all 4 plugs are firing.

 

[HenryB]

How was it running before the new fuel pump? It looks like it is running on prime, Otherwise it looks and sounds good. Can you get a photo of the snake spit? Can you pull the outlet tube from the pump to see if fuel is getting pumped on starter rpm?

 

[jstatham]

How was it running before the new fuel pump? It looks like it is running on prime, Otherwise it looks and sounds good. Can you get a photo of the snake spit? Can you pull the outlet tube from the pump to see if fuel is getting pumped on starter rpm?

The old vro pump was leaking but when I removed it and used the bulb directly connected to the carbs and manually pressed it and it ran the same. I will get a video of the snake spit tomorrow.

 

[HenryB]

Get a squirt bottle of mixed gas directly to the carb throat to see what happens.

 

[James R]

Hi. Does the motor sneeze before dying. Will the motor run if you have the idle lever on the controls in the fast idle position? If it will then lower the lever while shooting fuel mix into the carb throats. If it continues to run while you are shooting and dies when you stop we will have ascertained that it is a fuel problem at idle. When you cleaned the carbs did you remove the Welch plugs inside, clean the cavities and replace the plugs using a sealant. If so the sealant could be the problem. Lots of things to look at.

 

[jstatham]

Ok I could not wait until tomorrow so I just got in. Here is everything I did.

1. Rechecked the compression 120 all 4 cylinders
2. Checked fuel primer solenoid for leaks and I don’t think it is working properly see video link below. It only puts out a small drop of fuel when you press the key. I would think it would put out more.
3. Put in 4 Ql77jc4 plugs gapped at .30
4. I moved the coil on the cylinder that is dry from the top right to top left
5. I moved the plug wire from top right to bottom right
6. I moved the carb from Top Left to Bottom right facing the engine.
7. I check and made sure the fuel pump is pumping fuel when you turn it over by removing the out line that connect to the carbs. It squirted fuel fine when you turn the engine over
8. I also discover that one of the carbs had the Idle and intermediate air bleed orifices swapped. They look almost identical except for the number.

So the results are it seemed to run a little better but still want idle. It is still hissing and the top left carb is still snake spiting when the engine misses. You can see it very slightly in one of the video but it was getting dark and the video was not that great.
All the plugs seemed wet but could not get good pictures since it was dark. I can take better pictures tomorrow.

So I think we eliminated the coil, Plugs and wire being a problem.

Let me know what you think I should try next. Air/Fuel Mixture? Thanks in advance for all the help.

Solenoid video
http://home.comcast.net/~jkstatham/fuelprimer.mov

Motor Running snake spiting at beginning of video with different carb
http://home.comcast.net/~jkstatham/runningsnakespit.MOV

Running With breather

http://home.comcast.net/~jkstatham/running1withbreather.MOV


http://home.comcast.net/~jkstatham/running2.MOV

 

[HenryB]

Not sure pumping gas directly to carbs with primer ball a good idea. It may have put too much pressure on the carbs. The plugs should not be wet with fuel. Get yourself a cheap adjustable gap spark tester at the auto parts store set to 7/16" and check for a healty spark at dusk or well shaded. It might be flooding, but use the squirt bottle for effect.

 

[jstatham]

Hello everyone. It was another day of pulling out my hair but here is what I found. I checked the reeds and they all looked fine. I did find that the one of the fuel check valves hoses was broke so I replaced it as well as removed all 4 and cleaned them. I thought that would fix the problem but I still have the same issue. The top right plug is wet and all the others are fine. It will run for less than a minute and die. That top right carb is spitting gas out and I am assuming flooding and causing the engine to die. On that cylinder I have swapped carb,Plug, Wires and coil. I am now thinking my problem may be the power pack or rectifier. How can I test those? Also can you think of anything else I may have missed or anything else I can test.

 

[jstatham]

Here is a sparktest I did on the cylinder that has the wet plug and spitting carb. It looks like it is getting fire but I don't have the tester you can set the gap.

http://home.comcast.net/~jkstatham/sparktest.mov

 

[jstatham]

Here is a video of it running today and the spitting out of the carb. After seeing the video below do you still think it is a reed problem? Remember I swapped the carb to another cylinder and no matter what carb I put there it sill spits out of that orifice.

http://home.comcast.net/~jkstatham/spittingcarb.mov

 

[HenryB]

That is some wierd leak. Way over my head. Don't see no puff/spit from the carb to indicate a bad reed. But someone here has seen the condition before and will be able to explain it...I hope. If no response a reed block switch might do the trick, or an ebay used block. Double check o'rings/gaskets.

Sport for a ten dollar adjustable gap tester, they work the balls.

 

[jstatham]

Tonight I removed that carb and clean and inspected it again. I blew it out with my compressor and rechecked the needle and seat and float. There was green varnish on the brass tubes and I cleaned them the best I could. What does that mean? I was able to blow air through everywhere without any problems. I fired it up and it still ran rough and it is blowing off the check valve hose on the crank case part #

0392988. The carb overflow. I am not sure what this means but the plug is still dry and doing the same thing. I am going to move the carb to a different location tomorrow. It started raining and got dark,​

 

[HenryB]

Do a search on this site for 0392988. Not an uncommon problem. Joe Reeves knows how to handle it. I'm surprised that he has not chimed in yet.

Screwing around with that copper tube might bring more problems. It may have a very tiny hole at the bottom that will clog easy.

 

[daselbee]

Tonight I removed that carb and clean and inspected it again,[/CENTER]

What about the throttle bodies? Behind the round welch plug? Didn't touch that did you?

 

[jstatham]

Ok guys I broke down and had a Mobile Marine tech stop by last night and I have good news, bad news, and the ugly. First for the good news. All the carbs, powerpacks and basically everything I touched was perfect. The bad is that the one of the reasons is was missing and seemed like it was jumping time was because the piece that holds the timing rod in place is completely missing. According to the parts list its called the spark advanced link assembly part#

0432095​

. No big deal. Now for the ugly. While running we noticed that the fly wheel was bumping up and down and we could here a clunking noise. After further inspection we could see that the front of the crank case is damaged/cracked. He believes that the lower crank shaft bearing is shot and the crank is hitting the case. So now here is my question should I get a new front crank case cover and new bearings etc or just say screw it and part out the motor and get something else. I have a buddy who has a Johnson 115 that runs like a top and is good to go that he will sell me for $550. It may be a bit under powered for the boat but its better than nothing. I have not done the exact cost on how much all the parts who cost but assuming I can find a front crank cover it want be cheep. This motor has a new power pack, thermostats, water pump, previous owner said foot was rebuilt, fresh carb rebuild, optical sensor, plugs, etc. The compression is still 120 on all cylinders. The tech seem to think I could get probably $1000 if I part is out. The tech believes the motor was probably ran hot and that's what damaged the bearings and that also explains why the thermostats were missing. So let me know what you think and what would you do.

 

[jstatham]

I just spoke with my master marine mechanic in Kentucky and he said those bearing going out is a common problem and as long as it did not bust through I should be able to replace the bearing and I will be good to go. He said you could have a welder put a little weld on the outside just to be safe. I guess I am going to give it a try if a $30.00 bearing fixes it will be well worth it. I will let you know what happens.

 

[Dali30]

id say screw that air/fuel screws all the way in again (but not tight),and screw it 1.5 round out. i think its getting too much with your 2.5 rounds out. long time since i had an outboard with air/fuel screws,but im 99% sure it is 1.5 round out.

 

[HenryB]

Be careful. I see a perfectly good motor (really nice for its age) with a problem behind the carburetor, and not something welding on the block or changing bearings will fix that.

 

[HenryB]

A 115 is all you need, but 550 for one that runs like a top? I think you are being dragged in.