How do I remove 56 Johnson Javelin carb??

[KathyD19]

Love the engine, I have a 1956 15 hp Johnson oh and my wife too is a dental hygentist !

I have a love/hate relationship with this engine lol. It's the only one I've ever owned and I know it so darned intimately now so I will always have a soft spot for it. With all the issues I've had over the years, my hubby quipped "Why don't you get something newer than that....like maybe from the '70's??" Hahaha. So cool that you're wife is a hygienist too...give her a good back and shoulder rub, this job is hard on our bodies!! I'll tell ya, I sure found my dental skills handy when working on this motor. I'm used to working in tight places, I have little hands, I'm not afraid to get dirty and I'm ambidextrous so I was able to work two tools at a time using both hands. Maybe she can help you work on YOUR boat projects!

 

[flyingscott]

Yes adjust them both with a screwdriver to 1.5 turns open. Then put the knobs on with the pointer facing directly away from the nub.

 

[lindy46]

I use a little Seafoam in the gas on motors new to me - I figure it helps de-carbon them. I also use the aerosol "Deep Creep" and spray in the carb of a running motor to clean it out. WARNING - it will smoke like crazy!

 

[oldboat1]

Oh and one last thing..can I use Seafoam in the fuel for this engine? I use it for all my other gas powered devices and love it but I don't want to use it until I know it's ok.

https://youtu.be/TLh_hHNyeqA

Particularly after carb cleaning, I wouldn't put decarb solvents in the tank unless I knew for sure the tank was squeaky clean, and that the lines would stand up to solvents without giving off any nasties.

(Motor sounds good! Might add just a little more water -- and leave the hose running....)

Good Boating to you.

 

[KathyD19]

Failed the lake test. :blue: Started fine, put it in forward and started out slowly away from the dock. About 40 feet out, the engine started to surge and then fall back, doing that over and over on it's own. I upped the throttle a bit at the remote but it didn't respond, just kept doing the surge-fall back on it's own until it sputtered and died. I quickly pressed the start button without thinking about it being in forward gear yet it started anyhow. I thought there was a safety mechanism to stop that from happening? It still kept doing the surge then sputtered and died. The remote gear shift wouldn't go back into neutral (never had this happen before) but it would allow me to restart while in gear so I kept doing that after each surge-slow-die cycle until I limped back to the dock. At the dock I went to the motor and manually moved the lever into neutral, had no problem doing so then with the engine off and also the remote would move it fine with the engine off. Weird. Since I didn't trust the engine at that point with the surging, I did not try to put it in drive again. I restarted it while in neutral at the dock and took two short videos so you guys can see/hear it. This first link shows it surging and angrily shutting off. https://youtu.be/OVLF68Wfy60

The next one give you and idea of how it is revving and slowing down completely on it's own....I'm not touching a thing. #possessedmotor

https://youtu.be/uPgt2Jot8ao

I tried gently adjusting the slow speed needle on board while in neutral, only turning out a 1/4 turn but that did nothing. Gave up and took it home...only to wind up getting my truck stuck in mud by the driveway.. Fail day.

Suggestions as to what's going on? Did I put something back together incorrectly? Why did it work good in the barrel then do this nonsense at the lake? Thanks for sticking with this soap opera.

 

[KathyD19]

Anyone have any input or suggestions for me? Take a look at the two videos please and tell me what you think is going on.

 

[jimmbo]

Firing on both cylinders? Check the plugs for fouling. 35 yrs ago a fiends 25 was doing the surging thing and when the plugs were pulled, one had something bridging the gap.
Surging can also be a symptom of a lean carb or air leak.

 

[lindy46]

Yeah, sounds like a lean-sneeze to me. Turning the slow speed needle counterclockwise should have an effect and clear up the lean-sneeze. Is your packing nut tight enough to keep the barrel (which the needle screws into) from spinning in the casting? Try closing the needle altogether and see if it bottoms out.

 

[F_R]

In the second video, it would appear that you revved it up in neutral, causing the vacuum switch to cut out one cylinder. But it should have cut back in when it slowed down. Your first video shows it running terrible, and lean sneezing. Lean sneezing is caused by just that---too little fuel. But is is so bad, I don't know. Have you at least tried giving the carb needles a tweak toward rich?

Getting enough gas from the tank?

 

[flyingscott]

How did you set the float.

 

[jimmbo]

Having now watched the videos(hate doing it on the phone), I concur that that is sounds like a lean sneeze. Either dirt in the passages, or needle in too far

 

[KathyD19]

Firing on both cylinders? Check the plugs for fouling. 35 yrs ago a fiends 25 was doing the surging thing and when the plugs were pulled, one had something bridging the gap.
Surging can also be a symptom of a lean carb or air leak.

Put new plugs in before the barrel test which was right before the lake test. They don't look fouled afterwards.

 

[KathyD19]

Firing on both cylinders? Check the plugs for fouling. 35 yrs ago a fiends 25 was doing the surging thing and when the plugs were pulled, one had something bridging the gap.
Surging can also be a symptom of a lean carb or air leak.

I had put in new spark plugs before doing the barrel test, which was right before the lake test. Plugs aren't fouled after that either. Sounds like folks are agreeing on it being too lean so I'm going to look into that.

 

[KathyD19]

Yeah, sounds like a lean-sneeze to me. Turning the slow speed needle counterclockwise should have an effect and clear up the lean-sneeze. Is your packing nut tight enough to keep the barrel (which the needle screws into) from spinning in the casting? Try closing the needle altogether and see if it bottoms out.

I have never heard of a "lean-sneeze" before but that sure describes it! I had both needles turned out 1 1/2 turns as per the Joe Reeves instructions and I believed the pack nuts were tight enough but I'll redo it again before barrel testing.

 

[KathyD19]

In the second video, it would appear that you revved it up in neutral, causing the vacuum switch to cut out one cylinder. But it should have cut back in when it slowed down. Your first video shows it running terrible, and lean sneezing. Lean sneezing is caused by just that---too little fuel. But is is so bad, I don't know. Have you at least tried giving the carb needles a tweak toward rich?

Getting enough gas from the tank?

F_R In both videos I wasn't touching a thing, it did all the revving up on its own! It was bizarre. I did try to turn out the slow speed needle a quarter turn and there was no response from the motor.

 

[KathyD19]

How did you set the float.

I'm not sure what you mean by "setting" it? I installed the new float, checked to be sure it moved up and down correctly and also checked to be sure it was level with the rim of the base. I was prepared to adjust it if necessary but it actually was perfectly level.

 

[KathyD19]

I checked the tank and it seems fine, no leaks, has pressure, etc. Fuel lines are intact and attached, no cracks that I can see, no spilling fuel from the line. I DID notice one thing that caught my eye, though. The fuel filter glass bowl doesn't have much gas in it and I could also see a small air bubble at the bottom. I'll attach a picture. The fuel also doesn't look level, it looks like it's leaning towards the back of the motor. I don't think from looking at old pics that the glass bowl was ever completely full but I know it used to have more fuel in it than it appears to now. I know I put the new gasket/seal in when I redid the carb...maybe it's not seated correctly? Does that fuel filter bowl need to be airtight/vacuum?

 

[jimmbo]

Every fuel bowl I have ever seen, separate or on the fuel pump, was never ever full of fuel, but the engines would run fine

Initial setting for the needles were usually, 3/4 - 1 for the high speed and 1 1/2 for the idle.

 

[oldboat1]

air bubble in the bottom of the bowl, or water?

 

[KathyD19]

air bubble in the bottom of the bowl, or water?

Hmmm....interesting thought. Can I just unscrew and remove that glass bowl to inspect it better without having to remove the whole carb again?